diff --git a/tests/base.py b/tests/base.py
index 497d706..8efdfd1 100755
--- a/tests/base.py
+++ b/tests/base.py
@@ -50,6 +50,7 @@
 import zuul.rpclistener
 import zuul.launcher.gearman
 import zuul.lib.swift
+import zuul.lib.connections
 import zuul.merger.client
 import zuul.merger.merger
 import zuul.merger.server
@@ -864,6 +865,7 @@
 
 
 class ZuulTestCase(BaseTestCase):
+    config_file = 'zuul.conf'
 
     def setUp(self):
         super(ZuulTestCase, self).setUp()
@@ -907,6 +909,8 @@
         self.init_repo("org/experimental-project")
         self.init_repo("org/no-jobs-project")
 
+        self.setup_repos()
+
         self.statsd = FakeStatsd()
         # note, use 127.0.0.1 rather than localhost to avoid getting ipv6
         # see: https://github.com/jsocol/pystatsd/issues/61
@@ -940,7 +944,7 @@
             self.sched.trigger_event_queue
         ]
 
-        self.configure_connections()
+        self.configure_connections(self.sched)
         self.sched.registerConnections(self.connections)
 
         def URLOpenerFactory(*args, **kw):
@@ -979,7 +983,7 @@
         self.addCleanup(self.assertFinalState)
         self.addCleanup(self.shutdown)
 
-    def configure_connections(self):
+    def configure_connections(self, sched):
         # Register connections from the config
         self.smtp_messages = []
 
@@ -993,7 +997,7 @@
         # a virtual canonical database given by the configured hostname
         self.gerrit_changes_dbs = {}
         self.gerrit_queues_dbs = {}
-        self.connections = {}
+        self.connections = zuul.lib.connections.ConnectionRegistry(sched)
 
         for section_name in self.config.sections():
             con_match = re.match(r'^connection ([\'\"]?)(.*)(\1)$',
@@ -1018,15 +1022,16 @@
                         Queue.Queue()
                     self.event_queues.append(
                         self.gerrit_queues_dbs[con_config['server']])
-                self.connections[con_name] = FakeGerritConnection(
+                self.connections.connections[con_name] = FakeGerritConnection(
                     con_name, con_config,
                     changes_db=self.gerrit_changes_dbs[con_config['server']],
                     queues_db=self.gerrit_queues_dbs[con_config['server']],
                     upstream_root=self.upstream_root
                 )
-                setattr(self, 'fake_' + con_name, self.connections[con_name])
+                setattr(self, 'fake_' + con_name,
+                        self.connections.connections[con_name])
             elif con_driver == 'smtp':
-                self.connections[con_name] = \
+                self.connections.connections[con_name] = \
                     zuul.connection.smtp.SMTPConnection(con_name, con_config)
             else:
                 raise Exception("Unknown driver, %s, for connection %s"
@@ -1039,20 +1044,24 @@
             self.gerrit_changes_dbs['gerrit'] = {}
             self.gerrit_queues_dbs['gerrit'] = Queue.Queue()
             self.event_queues.append(self.gerrit_queues_dbs['gerrit'])
-            self.connections['gerrit'] = FakeGerritConnection(
+            self.connections.connections['gerrit'] = FakeGerritConnection(
                 '_legacy_gerrit', dict(self.config.items('gerrit')),
                 changes_db=self.gerrit_changes_dbs['gerrit'],
                 queues_db=self.gerrit_queues_dbs['gerrit'])
 
         if 'smtp' in self.config.sections():
-            self.connections['smtp'] = \
+            self.connections.connections['smtp'] = \
                 zuul.connection.smtp.SMTPConnection(
                     '_legacy_smtp', dict(self.config.items('smtp')))
 
-    def setup_config(self, config_file='zuul.conf'):
+    def setup_config(self):
         """Per test config object. Override to set different config."""
         self.config = ConfigParser.ConfigParser()
-        self.config.read(os.path.join(FIXTURE_DIR, config_file))
+        self.config.read(os.path.join(FIXTURE_DIR, self.config_file))
+
+    def setup_repos(self):
+        """Subclasses can override to manipulate repos before tests"""
+        pass
 
     def assertFinalState(self):
         # Make sure that git.Repo objects have been garbage collected.
@@ -1063,10 +1072,10 @@
                 repos.append(obj)
         self.assertEqual(len(repos), 0)
         self.assertEmptyQueues()
+        ipm = zuul.manager.independent.IndependentPipelineManager
         for tenant in self.sched.abide.tenants.values():
             for pipeline in tenant.layout.pipelines.values():
-                if isinstance(pipeline.manager,
-                              zuul.scheduler.IndependentPipelineManager):
+                if isinstance(pipeline.manager, ipm):
                     self.assertEqual(len(pipeline.queues), 0)
 
     def shutdown(self):
diff --git a/tests/fixtures/config/in-repo/common.yaml b/tests/fixtures/config/in-repo/common.yaml
index 96aebd6..f38406b 100644
--- a/tests/fixtures/config/in-repo/common.yaml
+++ b/tests/fixtures/config/in-repo/common.yaml
@@ -1,6 +1,6 @@
 pipelines:
   - name: check
-    manager: IndependentPipelineManager
+    manager: independent
     source:
       gerrit
     trigger:
@@ -14,7 +14,7 @@
         verified: -1
 
   - name: tenant-one-gate
-    manager: DependentPipelineManager
+    manager: dependent
     success-message: Build succeeded (tenant-one-gate).
     source:
       gerrit
diff --git a/tests/fixtures/config/in-repo/zuul.conf b/tests/fixtures/config/in-repo/zuul.conf
index 14708aa..1910084 100644
--- a/tests/fixtures/config/in-repo/zuul.conf
+++ b/tests/fixtures/config/in-repo/zuul.conf
@@ -2,7 +2,7 @@
 server=127.0.0.1
 
 [zuul]
-tenant_config=tests/fixtures/config/in-repo/main.yaml
+tenant_config=config/in-repo/main.yaml
 url_pattern=http://logs.example.com/{change.number}/{change.patchset}/{pipeline.name}/{job.name}/{build.number}
 job_name_in_report=true
 
diff --git a/tests/fixtures/config/multi-tenant/common.yaml b/tests/fixtures/config/multi-tenant/common.yaml
index d36448e..8fc3bba 100644
--- a/tests/fixtures/config/multi-tenant/common.yaml
+++ b/tests/fixtures/config/multi-tenant/common.yaml
@@ -1,6 +1,6 @@
 pipelines:
   - name: check
-    manager: IndependentPipelineManager
+    manager: independent
     source:
       gerrit
     trigger:
diff --git a/tests/fixtures/config/multi-tenant/tenant-one.yaml b/tests/fixtures/config/multi-tenant/tenant-one.yaml
index 7b2298c..c9096ef 100644
--- a/tests/fixtures/config/multi-tenant/tenant-one.yaml
+++ b/tests/fixtures/config/multi-tenant/tenant-one.yaml
@@ -1,6 +1,6 @@
 pipelines:
   - name: tenant-one-gate
-    manager: DependentPipelineManager
+    manager: dependent
     success-message: Build succeeded (tenant-one-gate).
     source:
       gerrit
@@ -21,6 +21,10 @@
         verified: 0
     precedence: high
 
+jobs:
+  - name:
+      project1-test1
+
 projects:
   - name: org/project1
     check:
diff --git a/tests/fixtures/config/multi-tenant/tenant-two.yaml b/tests/fixtures/config/multi-tenant/tenant-two.yaml
index 57ad64d..6cb2d9a 100644
--- a/tests/fixtures/config/multi-tenant/tenant-two.yaml
+++ b/tests/fixtures/config/multi-tenant/tenant-two.yaml
@@ -1,6 +1,6 @@
 pipelines:
   - name: tenant-two-gate
-    manager: DependentPipelineManager
+    manager: dependent
     success-message: Build succeeded (tenant-two-gate).
     source:
       gerrit
@@ -21,6 +21,10 @@
         verified: 0
     precedence: high
 
+jobs:
+  - name:
+      project2-test1
+
 projects:
   - name: org/project2
     check:
diff --git a/tests/fixtures/config/multi-tenant/zuul.conf b/tests/fixtures/config/multi-tenant/zuul.conf
index ceb3903..346450e 100644
--- a/tests/fixtures/config/multi-tenant/zuul.conf
+++ b/tests/fixtures/config/multi-tenant/zuul.conf
@@ -2,7 +2,7 @@
 server=127.0.0.1
 
 [zuul]
-tenant_config=tests/fixtures/config/multi-tenant/main.yaml
+tenant_config=config/multi-tenant/main.yaml
 url_pattern=http://logs.example.com/{change.number}/{change.patchset}/{pipeline.name}/{job.name}/{build.number}
 job_name_in_report=true
 
diff --git a/tests/fixtures/layout.yaml b/tests/fixtures/layout.yaml
index 99b135c..e30147f 100644
--- a/tests/fixtures/layout.yaml
+++ b/tests/fixtures/layout.yaml
@@ -3,7 +3,7 @@
 
 pipelines:
   - name: check
-    manager: IndependentPipelineManager
+    manager: independent
     source:
       gerrit
     trigger:
@@ -17,7 +17,7 @@
         verified: -1
 
   - name: post
-    manager: IndependentPipelineManager
+    manager: independent
     source:
       gerrit
     trigger:
@@ -26,7 +26,7 @@
           ref: ^(?!refs/).*$
 
   - name: gate
-    manager: DependentPipelineManager
+    manager: dependent
     failure-message: Build failed.  For information on how to proceed, see http://wiki.example.org/Test_Failures
     source:
       gerrit
@@ -48,7 +48,7 @@
     precedence: high
 
   - name: unused
-    manager: IndependentPipelineManager
+    manager: independent
     dequeue-on-new-patchset: false
     source:
       gerrit
@@ -59,7 +59,7 @@
             - approved: 1
 
   - name: dup1
-    manager: IndependentPipelineManager
+    manager: independent
     source:
       gerrit
     trigger:
@@ -73,7 +73,7 @@
         verified: -1
 
   - name: dup2
-    manager: IndependentPipelineManager
+    manager: independent
     source:
       gerrit
     trigger:
@@ -87,7 +87,7 @@
         verified: -1
 
   - name: conflict
-    manager: DependentPipelineManager
+    manager: dependent
     failure-message: Build failed.  For information on how to proceed, see http://wiki.example.org/Test_Failures
     source:
       gerrit
@@ -108,7 +108,7 @@
         verified: 0
 
   - name: experimental
-    manager: IndependentPipelineManager
+    manager: independent
     source:
       gerrit
     trigger:
diff --git a/tests/test_layoutvalidator.py b/tests/test_layoutvalidator.py
index 3dc3234..bd507d1 100644
--- a/tests/test_layoutvalidator.py
+++ b/tests/test_layoutvalidator.py
@@ -31,6 +31,9 @@
 
 
 class TestLayoutValidator(testtools.TestCase):
+    def setUp(self):
+        self.skip("Disabled for early v3 development")
+
     def test_layouts(self):
         """Test layout file validation"""
         print
diff --git a/tests/test_merger_repo.py b/tests/test_merger_repo.py
index 454f3cc..7bf08ee 100644
--- a/tests/test_merger_repo.py
+++ b/tests/test_merger_repo.py
@@ -34,8 +34,11 @@
     workspace_root = None
 
     def setUp(self):
-        super(TestMergerRepo, self).setUp()
-        self.workspace_root = os.path.join(self.test_root, 'workspace')
+        self.skip("Disabled for early v3 development")
+
+    # def setUp(self):
+    #     super(TestMergerRepo, self).setUp()
+    #     self.workspace_root = os.path.join(self.test_root, 'workspace')
 
     def test_ensure_cloned(self):
         parent_path = os.path.join(self.upstream_root, 'org/project1')
diff --git a/tests/test_model.py b/tests/test_model.py
index d4c7880..f8f74dc 100644
--- a/tests/test_model.py
+++ b/tests/test_model.py
@@ -12,8 +12,8 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-from zuul import change_matcher as cm
 from zuul import model
+from zuul import configloader
 
 from tests.base import BaseTestCase
 
@@ -22,11 +22,12 @@
 
     @property
     def job(self):
-        job = model.Job('job')
-        job.skip_if_matcher = cm.MatchAll([
-            cm.ProjectMatcher('^project$'),
-            cm.MatchAllFiles([cm.FileMatcher('^docs/.*$')]),
-        ])
+        layout = model.Layout()
+        job = configloader.JobParser.fromYaml(layout, {
+            'name': 'job',
+            'irrelevant-files': [
+                '^docs/.*$'
+            ]})
         return job
 
     def test_change_matches_returns_false_for_matched_skip_if(self):
@@ -39,10 +40,61 @@
         change.files = ['foo']
         self.assertTrue(self.job.changeMatches(change))
 
-    def _assert_job_booleans_are_not_none(self, job):
-        self.assertIsNotNone(job.voting)
-        self.assertIsNotNone(job.hold_following_changes)
-
     def test_job_sets_defaults_for_boolean_attributes(self):
-        job = model.Job('job')
-        self._assert_job_booleans_are_not_none(job)
+        self.assertIsNotNone(self.job.voting)
+
+    def test_job_inheritance(self):
+        layout = model.Layout()
+        base = configloader.JobParser.fromYaml(layout, {
+            'name': 'base',
+            'timeout': 30,
+        })
+        layout.addJob(base)
+        python27 = configloader.JobParser.fromYaml(layout, {
+            'name': 'python27',
+            'parent': 'base',
+            'timeout': 40,
+        })
+        layout.addJob(python27)
+        python27diablo = configloader.JobParser.fromYaml(layout, {
+            'name': 'python27',
+            'branches': [
+                'stable/diablo'
+            ],
+            'timeout': 50,
+        })
+        layout.addJob(python27diablo)
+
+        pipeline = model.Pipeline('gate', layout)
+        layout.addPipeline(pipeline)
+        queue = model.ChangeQueue(pipeline)
+
+        project = model.Project('project')
+        tree = pipeline.addProject(project)
+        tree.addJob(layout.getJob('python27'))
+
+        change = model.Change(project)
+        change.branch = 'master'
+        item = queue.enqueueChange(change)
+
+        self.assertTrue(base.changeMatches(change))
+        self.assertTrue(python27.changeMatches(change))
+        self.assertFalse(python27diablo.changeMatches(change))
+
+        item.freezeJobTree()
+        self.assertEqual(len(item.getJobs()), 1)
+        job = item.getJobs()[0]
+        self.assertEqual(job.name, 'python27')
+        self.assertEqual(job.timeout, 40)
+
+        change.branch = 'stable/diablo'
+
+        self.assertTrue(base.changeMatches(change))
+        self.assertTrue(python27.changeMatches(change))
+        self.assertTrue(python27diablo.changeMatches(change))
+
+        item.freezeJobTree()
+        self.assertEqual(len(item.getJobs()), 1)
+        job = item.getJobs()[0]
+        self.assertEqual(job.name, 'python27')
+        self.assertEqual(job.timeout, 50)
diff --git a/tests/test_scheduler.py b/tests/test_scheduler.py
index 7ef166c..85ac600 100755
--- a/tests/test_scheduler.py
+++ b/tests/test_scheduler.py
@@ -46,6 +46,9 @@
 
 class TestSchedulerConfigParsing(BaseTestCase):
 
+    def setUp(self):
+        self.skip("Disabled for early v3 development")
+
     def test_parse_skip_if(self):
         job_yaml = """
 jobs:
diff --git a/tests/test_v3.py b/tests/test_v3.py
index 69e66a0..73efcc9 100644
--- a/tests/test_v3.py
+++ b/tests/test_v3.py
@@ -26,13 +26,12 @@
                     '%(levelname)-8s %(message)s')
 
 
-class TestV3(ZuulTestCase):
+class TestMultipleTenants(ZuulTestCase):
     # A temporary class to hold new tests while others are disabled
 
-    def test_multiple_tenants(self):
-        self.setup_config('config/multi-tenant/zuul.conf')
-        self.sched.reconfigure(self.config)
+    config_file = 'config/multi-tenant/zuul.conf'
 
+    def test_multiple_tenants(self):
         A = self.fake_gerrit.addFakeChange('org/project1', 'master', 'A')
         A.addApproval('CRVW', 2)
         self.fake_gerrit.addEvent(A.addApproval('APRV', 1))
@@ -64,9 +63,18 @@
         self.assertEqual(A.reported, 2, "Activity in tenant two should"
                          "not affect tenant one")
 
-    def test_in_repo_config(self):
+
+class TestInRepoConfig(ZuulTestCase):
+    # A temporary class to hold new tests while others are disabled
+
+    config_file = 'config/in-repo/zuul.conf'
+
+    def setup_repos(self):
         in_repo_conf = textwrap.dedent(
             """
+            jobs:
+              - name: project-test1
+
             projects:
               - name: org/project
                 tenant-one-gate:
@@ -76,9 +84,7 @@
         self.addCommitToRepo('org/project', 'add zuul conf',
                              {'.zuul.yaml': in_repo_conf})
 
-        self.setup_config('config/in-repo/zuul.conf')
-        self.sched.reconfigure(self.config)
-
+    def test_in_repo_config(self):
         A = self.fake_gerrit.addFakeChange('org/project', 'master', 'A')
         A.addApproval('CRVW', 2)
         self.fake_gerrit.addEvent(A.addApproval('APRV', 1))
diff --git a/zuul/cmd/__init__.py b/zuul/cmd/__init__.py
index 2902c50..f6b9fe1 100644
--- a/zuul/cmd/__init__.py
+++ b/zuul/cmd/__init__.py
@@ -90,6 +90,6 @@
         else:
             logging.basicConfig(level=logging.DEBUG)
 
-    def configure_connections(self):
-        self.connections = zuul.lib.connections.configure_connections(
-            self.config)
+    def configure_connections(self, sched):
+        self.connections = zuul.lib.connections.ConnectionRegistry()
+        self.connections.configure(self.config, sched)
diff --git a/zuul/cmd/server.py b/zuul/cmd/server.py
index 2aca4f2..2c891b5 100755
--- a/zuul/cmd/server.py
+++ b/zuul/cmd/server.py
@@ -177,7 +177,7 @@
         webapp = zuul.webapp.WebApp(self.sched, cache_expiry=cache_expiry)
         rpc = zuul.rpclistener.RPCListener(self.config, self.sched)
 
-        self.configure_connections()
+        self.configure_connections(self.sched)
         self.sched.setLauncher(gearman)
         self.sched.setMerger(merger)
 
diff --git a/zuul/configloader.py b/zuul/configloader.py
new file mode 100644
index 0000000..d22106d
--- /dev/null
+++ b/zuul/configloader.py
@@ -0,0 +1,449 @@
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import os
+import logging
+import yaml
+
+import voluptuous as vs
+
+import model
+import zuul.manager
+import zuul.manager.dependent
+import zuul.manager.independent
+from zuul import change_matcher
+
+
+# Several forms accept either a single item or a list, this makes
+# specifying that in the schema easy (and explicit).
+def to_list(x):
+    return vs.Any([x], x)
+
+
+def as_list(item):
+    if not item:
+        return []
+    if isinstance(item, list):
+        return item
+    return [item]
+
+
+def extend_dict(a, b):
+    """Extend dictionary a (which will be modified in place) with the
+       contents of b.  This is designed for Zuul yaml files which are
+       typically dictionaries of lists of dictionaries, e.g.,
+       {'pipelines': ['name': 'gate']}.  If two such dictionaries each
+       define a pipeline, the result will be a single dictionary with
+       a pipelines entry whose value is a two-element list."""
+
+    for k, v in b.items():
+        if k not in a:
+            a[k] = v
+        elif isinstance(v, dict) and isinstance(a[k], dict):
+            extend_dict(a[k], v)
+        elif isinstance(v, list) and isinstance(a[k], list):
+            a[k] += v
+        elif isinstance(v, list):
+            a[k] = [a[k]] + v
+        elif isinstance(a[k], list):
+            a[k] += [v]
+        else:
+            raise Exception("Unhandled case in extend_dict at %s" % (k,))
+
+
+def deep_format(obj, paramdict):
+    """Apply the paramdict via str.format() to all string objects found within
+       the supplied obj. Lists and dicts are traversed recursively.
+
+       Borrowed from Jenkins Job Builder project"""
+    if isinstance(obj, str):
+        ret = obj.format(**paramdict)
+    elif isinstance(obj, list):
+        ret = []
+        for item in obj:
+            ret.append(deep_format(item, paramdict))
+    elif isinstance(obj, dict):
+        ret = {}
+        for item in obj:
+            exp_item = item.format(**paramdict)
+
+            ret[exp_item] = deep_format(obj[item], paramdict)
+    else:
+        ret = obj
+    return ret
+
+
+class JobParser(object):
+    @staticmethod
+    def getSchema():
+        # TODOv3(jeblair, jhesketh): move to auth
+        swift = {vs.Required('name'): str,
+                 'container': str,
+                 'expiry': int,
+                 'max_file_size': int,
+                 'max-file-size': int,
+                 'max_file_count': int,
+                 'max-file-count': int,
+                 'logserver_prefix': str,
+                 'logserver-prefix': str,
+                 }
+
+        job = {vs.Required('name'): str,
+               'parent': str,
+               'queue-name': str,
+               'failure-message': str,
+               'success-message': str,
+               'failure-url': str,
+               'success-url': str,
+               'voting': bool,
+               'branches': to_list(str),
+               'files': to_list(str),
+               'swift': to_list(swift),
+               'irrelevant-files': to_list(str),
+               'timeout': int,
+               }
+
+        return vs.Schema(job)
+
+    @staticmethod
+    def fromYaml(layout, conf):
+        JobParser.getSchema()(conf)
+        job = model.Job(conf['name'])
+        if 'parent' in conf:
+            parent = layout.getJob(conf['parent'])
+            job.inheritFrom(parent)
+        job.timeout = conf.get('timeout', job.timeout)
+        job.workspace = conf.get('workspace', job.workspace)
+        job.pre_run = as_list(conf.get('pre-run', job.pre_run))
+        job.post_run = as_list(conf.get('post-run', job.post_run))
+        job.voting = conf.get('voting', True)
+
+        job.failure_message = conf.get('failure-message', job.failure_message)
+        job.success_message = conf.get('success-message', job.success_message)
+        job.failure_url = conf.get('failure-url', job.failure_url)
+        job.success_url = conf.get('success-url', job.success_url)
+        if 'branches' in conf:
+            matchers = []
+            for branch in as_list(conf['branches']):
+                matchers.append(change_matcher.BranchMatcher(branch))
+            job.branch_matcher = change_matcher.MatchAny(matchers)
+        if 'files' in conf:
+            matchers = []
+            for fn in as_list(conf['files']):
+                matchers.append(change_matcher.FileMatcher(fn))
+            job.file_matcher = change_matcher.MatchAny(matchers)
+        if 'irrelevant-files' in conf:
+            matchers = []
+            for fn in as_list(conf['irrelevant-files']):
+                matchers.append(change_matcher.FileMatcher(fn))
+            job.irrelevant_file_matcher = change_matcher.MatchAllFiles(
+                matchers)
+        return job
+
+
+class AbideValidator(object):
+    tenant_source = vs.Schema({'repos': [str]})
+
+    def validateTenantSources(self, connections):
+        def v(value, path=[]):
+            if isinstance(value, dict):
+                for k, val in value.items():
+                    connections.getSource(k)
+                    self.validateTenantSource(val, path + [k])
+            else:
+                raise vs.Invalid("Invalid tenant source", path)
+        return v
+
+    def validateTenantSource(self, value, path=[]):
+        self.tenant_source(value)
+
+    def getSchema(self, connections=None):
+        tenant = {vs.Required('name'): str,
+                  'include': to_list(str),
+                  'source': self.validateTenantSources(connections)}
+
+        schema = vs.Schema({'tenants': [tenant]})
+
+        return schema
+
+    def validate(self, data, connections=None):
+        schema = self.getSchema(connections)
+        schema(data)
+
+
+class ConfigLoader(object):
+    log = logging.getLogger("zuul.ConfigLoader")
+
+    # A set of reporter configuration keys to action mapping
+    reporter_actions = {
+        'start': 'start_actions',
+        'success': 'success_actions',
+        'failure': 'failure_actions',
+        'merge-failure': 'merge_failure_actions',
+        'disabled': 'disabled_actions',
+    }
+
+    def loadConfig(self, config_path, scheduler, merger, connections):
+        abide = model.Abide()
+
+        if config_path:
+            config_path = os.path.expanduser(config_path)
+            if not os.path.exists(config_path):
+                raise Exception("Unable to read tenant config file at %s" %
+                                config_path)
+        with open(config_path) as config_file:
+            self.log.info("Loading configuration from %s" % (config_path,))
+            data = yaml.load(config_file)
+        base = os.path.dirname(os.path.realpath(config_path))
+
+        validator = AbideValidator()
+        validator.validate(data, connections)
+
+        for conf_tenant in data['tenants']:
+            tenant = model.Tenant(conf_tenant['name'])
+            abide.tenants[tenant.name] = tenant
+            tenant_config = {}
+            for fn in conf_tenant.get('include', []):
+                if not os.path.isabs(fn):
+                    fn = os.path.join(base, fn)
+                fn = os.path.expanduser(fn)
+                with open(fn) as config_file:
+                    self.log.info("Loading configuration from %s" % (fn,))
+                    incdata = yaml.load(config_file)
+                    extend_dict(tenant_config, incdata)
+            incdata = self._loadTenantInRepoLayouts(merger, connections,
+                                                    conf_tenant)
+            extend_dict(tenant_config, incdata)
+            tenant.layout = self._parseLayout(base, tenant_config,
+                                              scheduler, connections)
+        return abide
+
+    def _parseLayout(self, base, data, scheduler, connections):
+        layout = model.Layout()
+        project_templates = {}
+
+        # TODOv3(jeblair): add validation
+        # validator = layoutvalidator.LayoutValidator()
+        # validator.validate(data, connections)
+
+        config_env = {}
+        for include in data.get('includes', []):
+            if 'python-file' in include:
+                fn = include['python-file']
+                if not os.path.isabs(fn):
+                    fn = os.path.join(base, fn)
+                fn = os.path.expanduser(fn)
+                execfile(fn, config_env)
+
+        for conf_pipeline in data.get('pipelines', []):
+            pipeline = model.Pipeline(conf_pipeline['name'], layout)
+            pipeline.description = conf_pipeline.get('description')
+
+            pipeline.source = connections.getSource(conf_pipeline['source'])
+
+            precedence = model.PRECEDENCE_MAP[conf_pipeline.get('precedence')]
+            pipeline.precedence = precedence
+            pipeline.failure_message = conf_pipeline.get('failure-message',
+                                                         "Build failed.")
+            pipeline.merge_failure_message = conf_pipeline.get(
+                'merge-failure-message', "Merge Failed.\n\nThis change or one "
+                "of its cross-repo dependencies was unable to be "
+                "automatically merged with the current state of its "
+                "repository. Please rebase the change and upload a new "
+                "patchset.")
+            pipeline.success_message = conf_pipeline.get('success-message',
+                                                         "Build succeeded.")
+            pipeline.footer_message = conf_pipeline.get('footer-message', "")
+            pipeline.dequeue_on_new_patchset = conf_pipeline.get(
+                'dequeue-on-new-patchset', True)
+            pipeline.ignore_dependencies = conf_pipeline.get(
+                'ignore-dependencies', False)
+
+            for conf_key, action in self.reporter_actions.items():
+                reporter_set = []
+                if conf_pipeline.get(conf_key):
+                    for reporter_name, params \
+                        in conf_pipeline.get(conf_key).items():
+                        reporter = connections.getReporter(reporter_name,
+                                                           params)
+                        reporter.setAction(conf_key)
+                        reporter_set.append(reporter)
+                setattr(pipeline, action, reporter_set)
+
+            # If merge-failure actions aren't explicit, use the failure actions
+            if not pipeline.merge_failure_actions:
+                pipeline.merge_failure_actions = pipeline.failure_actions
+
+            pipeline.disable_at = conf_pipeline.get(
+                'disable-after-consecutive-failures', None)
+
+            pipeline.window = conf_pipeline.get('window', 20)
+            pipeline.window_floor = conf_pipeline.get('window-floor', 3)
+            pipeline.window_increase_type = conf_pipeline.get(
+                'window-increase-type', 'linear')
+            pipeline.window_increase_factor = conf_pipeline.get(
+                'window-increase-factor', 1)
+            pipeline.window_decrease_type = conf_pipeline.get(
+                'window-decrease-type', 'exponential')
+            pipeline.window_decrease_factor = conf_pipeline.get(
+                'window-decrease-factor', 2)
+
+            manager_name = conf_pipeline['manager']
+            if manager_name == 'dependent':
+                manager = zuul.manager.dependent.DependentPipelineManager(
+                    scheduler, pipeline)
+            elif manager_name == 'independent':
+                manager = zuul.manager.independent.IndependentPipelineManager(
+                    scheduler, pipeline)
+
+            pipeline.setManager(manager)
+            layout.pipelines[conf_pipeline['name']] = pipeline
+
+            if 'require' in conf_pipeline or 'reject' in conf_pipeline:
+                require = conf_pipeline.get('require', {})
+                reject = conf_pipeline.get('reject', {})
+                f = model.ChangeishFilter(
+                    open=require.get('open'),
+                    current_patchset=require.get('current-patchset'),
+                    statuses=to_list(require.get('status')),
+                    required_approvals=to_list(require.get('approval')),
+                    reject_approvals=to_list(reject.get('approval'))
+                )
+                manager.changeish_filters.append(f)
+
+            for trigger_name, trigger_config\
+                in conf_pipeline.get('trigger').items():
+                trigger = connections.getTrigger(trigger_name, trigger_config)
+                pipeline.triggers.append(trigger)
+
+                # TODO: move
+                manager.event_filters += trigger.getEventFilters(
+                    conf_pipeline['trigger'][trigger_name])
+
+        for project_template in data.get('project-templates', []):
+            # Make sure the template only contains valid pipelines
+            tpl = dict(
+                (pipe_name, project_template.get(pipe_name))
+                for pipe_name in layout.pipelines.keys()
+                if pipe_name in project_template
+            )
+            project_templates[project_template.get('name')] = tpl
+
+        for config_job in data.get('jobs', []):
+            layout.addJob(JobParser.fromYaml(layout, config_job))
+
+        def add_jobs(job_tree, config_jobs):
+            for job in config_jobs:
+                if isinstance(job, list):
+                    for x in job:
+                        add_jobs(job_tree, x)
+                if isinstance(job, dict):
+                    for parent, children in job.items():
+                        parent_tree = job_tree.addJob(layout.getJob(parent))
+                        add_jobs(parent_tree, children)
+                if isinstance(job, str):
+                    job_tree.addJob(layout.getJob(job))
+
+        for config_project in data.get('projects', []):
+            shortname = config_project['name'].split('/')[-1]
+
+            # This is reversed due to the prepend operation below, so
+            # the ultimate order is templates (in order) followed by
+            # statically defined jobs.
+            for requested_template in reversed(
+                config_project.get('template', [])):
+                # Fetch the template from 'project-templates'
+                tpl = project_templates.get(
+                    requested_template.get('name'))
+                # Expand it with the project context
+                requested_template['name'] = shortname
+                expanded = deep_format(tpl, requested_template)
+                # Finally merge the expansion with whatever has been
+                # already defined for this project.  Prepend our new
+                # jobs to existing ones (which may have been
+                # statically defined or defined by other templates).
+                for pipeline in layout.pipelines.values():
+                    if pipeline.name in expanded:
+                        config_project.update(
+                            {pipeline.name: expanded[pipeline.name] +
+                             config_project.get(pipeline.name, [])})
+
+            mode = config_project.get('merge-mode', 'merge-resolve')
+            for pipeline in layout.pipelines.values():
+                if pipeline.name in config_project:
+                    project = pipeline.source.getProject(
+                        config_project['name'])
+                    project.merge_mode = model.MERGER_MAP[mode]
+                    job_tree = pipeline.addProject(project)
+                    config_jobs = config_project[pipeline.name]
+                    add_jobs(job_tree, config_jobs)
+
+        for pipeline in layout.pipelines.values():
+            pipeline.manager._postConfig(layout)
+
+        return layout
+
+    def _loadTenantInRepoLayouts(self, merger, connections, conf_tenant):
+        config = {}
+        jobs = []
+        for source_name, conf_source in conf_tenant.get('source', {}).items():
+            source = connections.getSource(source_name)
+            for conf_repo in conf_source.get('repos'):
+                project = source.getProject(conf_repo)
+                url = source.getGitUrl(project)
+                # TODOv3(jeblair): config should be branch specific
+                job = merger.getFiles(project.name, url, 'master',
+                                      files=['.zuul.yaml'])
+                job.project = project
+                jobs.append(job)
+        for job in jobs:
+            self.log.debug("Waiting for cat job %s" % (job,))
+            job.wait()
+            if job.files.get('.zuul.yaml'):
+                self.log.info("Loading configuration from %s/.zuul.yaml" %
+                              (job.project,))
+                incdata = self._parseInRepoLayout(job.files['.zuul.yaml'])
+                extend_dict(config, incdata)
+        return config
+
+    def _parseInRepoLayout(self, data):
+        # TODOv3(jeblair): this should implement some rules to protect
+        # aspects of the config that should not be changed in-repo
+        return yaml.load(data)
+
+    def _parseSkipIf(self, config_job):
+        cm = change_matcher
+        skip_matchers = []
+
+        for config_skip in config_job.get('skip-if', []):
+            nested_matchers = []
+
+            project_regex = config_skip.get('project')
+            if project_regex:
+                nested_matchers.append(cm.ProjectMatcher(project_regex))
+
+            branch_regex = config_skip.get('branch')
+            if branch_regex:
+                nested_matchers.append(cm.BranchMatcher(branch_regex))
+
+            file_regexes = to_list(config_skip.get('all-files-match-any'))
+            if file_regexes:
+                file_matchers = [cm.FileMatcher(x) for x in file_regexes]
+                all_files_matcher = cm.MatchAllFiles(file_matchers)
+                nested_matchers.append(all_files_matcher)
+
+            # All patterns need to match a given skip-if predicate
+            skip_matchers.append(cm.MatchAll(nested_matchers))
+
+        if skip_matchers:
+            # Any skip-if predicate can be matched to trigger a skip
+            return cm.MatchAny(skip_matchers)
diff --git a/zuul/connection/gerrit.py b/zuul/connection/gerrit.py
index 8d2e771..a203c24 100644
--- a/zuul/connection/gerrit.py
+++ b/zuul/connection/gerrit.py
@@ -25,7 +25,7 @@
 import urllib2
 
 from zuul.connection import BaseConnection
-from zuul.model import TriggerEvent
+from zuul.model import TriggerEvent, Project
 
 
 class GerritEventConnector(threading.Thread):
@@ -221,8 +221,14 @@
                                                   'https://%s' % self.server)
 
         self._change_cache = {}
+        self.projects = {}
         self.gerrit_event_connector = None
 
+    def getProject(self, name):
+        if name not in self.projects:
+            self.projects[name] = Project(name)
+        return self.projects[name]
+
     def getCachedChange(self, key):
         if key in self._change_cache:
             return self._change_cache.get(key)
diff --git a/zuul/lib/connections.py b/zuul/lib/connections.py
index cb26ba5..5f42c3a 100644
--- a/zuul/lib/connections.py
+++ b/zuul/lib/connections.py
@@ -18,49 +18,113 @@
 import zuul.connection.smtp
 
 
-def configure_connections(config):
-    # Register connections from the config
+class ConnectionRegistry(object):
+    """A registry of connections"""
 
-    # TODO(jhesketh): import connection modules dynamically
-    connections = {}
+    def __init__(self, sched):
+        self.connections = {}
+        self.sched = sched  # TODOv3(jeblair): remove (abstraction violation)
 
-    for section_name in config.sections():
-        con_match = re.match(r'^connection ([\'\"]?)(.*)(\1)$',
-                             section_name, re.I)
-        if not con_match:
-            continue
-        con_name = con_match.group(2)
-        con_config = dict(config.items(section_name))
+    def registerScheduler(self, sched):
+        for connection_name, connection in self.connections.items():
+            connection.registerScheduler(sched)
+            connection.onLoad()
 
-        if 'driver' not in con_config:
-            raise Exception("No driver specified for connection %s."
-                            % con_name)
+    def stop(self):
+        for connection_name, connection in self.connections.items():
+            connection.onStop()
 
-        con_driver = con_config['driver']
+    def configure(self, config):
+        # Register connections from the config
+        # TODO(jhesketh): import connection modules dynamically
+        connections = {}
 
-        # TODO(jhesketh): load the required class automatically
-        if con_driver == 'gerrit':
-            connections[con_name] = \
-                zuul.connection.gerrit.GerritConnection(con_name,
-                                                        con_config)
-        elif con_driver == 'smtp':
-            connections[con_name] = \
-                zuul.connection.smtp.SMTPConnection(con_name, con_config)
+        for section_name in config.sections():
+            con_match = re.match(r'^connection ([\'\"]?)(.*)(\1)$',
+                                 section_name, re.I)
+            if not con_match:
+                continue
+            con_name = con_match.group(2)
+            con_config = dict(config.items(section_name))
+
+            if 'driver' not in con_config:
+                raise Exception("No driver specified for connection %s."
+                                % con_name)
+
+            con_driver = con_config['driver']
+
+            # TODO(jhesketh): load the required class automatically
+            if con_driver == 'gerrit':
+                connections[con_name] = \
+                    zuul.connection.gerrit.GerritConnection(con_name,
+                                                            con_config)
+            elif con_driver == 'smtp':
+                connections[con_name] = \
+                    zuul.connection.smtp.SMTPConnection(con_name, con_config)
+            else:
+                raise Exception("Unknown driver, %s, for connection %s"
+                                % (con_config['driver'], con_name))
+
+        # If the [gerrit] or [smtp] sections still exist, load them in as a
+        # connection named 'gerrit' or 'smtp' respectfully
+
+        if 'gerrit' in config.sections():
+            connections['gerrit'] = \
+                zuul.connection.gerrit.GerritConnection(
+                    '_legacy_gerrit', dict(config.items('gerrit')))
+
+        if 'smtp' in config.sections():
+            connections['smtp'] = \
+                zuul.connection.smtp.SMTPConnection(
+                    '_legacy_smtp', dict(config.items('smtp')))
+
+        self.connections = connections
+
+    def _getDriver(self, dtype, connection_name, driver_config={}):
+        # Instantiate a driver such as a trigger, source or reporter
+        # TODO(jhesketh): Make this list dynamic or use entrypoints etc.
+        # Stevedore was not a good fit here due to the nature of triggers.
+        # Specifically we don't want to load a trigger per a pipeline as one
+        # trigger can listen to a stream (from gerrit, for example) and the
+        # scheduler decides which eventfilter to use. As such we want to load
+        # trigger+connection pairs uniquely.
+        drivers = {
+            'source': {
+                'gerrit': 'zuul.source.gerrit:GerritSource',
+            },
+            'trigger': {
+                'gerrit': 'zuul.trigger.gerrit:GerritTrigger',
+                'timer': 'zuul.trigger.timer:TimerTrigger',
+                'zuul': 'zuul.trigger.zuultrigger:ZuulTrigger',
+            },
+            'reporter': {
+                'gerrit': 'zuul.reporter.gerrit:GerritReporter',
+                'smtp': 'zuul.reporter.smtp:SMTPReporter',
+            },
+        }
+
+        # TODO(jhesketh): Check the connection_name exists
+        if connection_name in self.connections.keys():
+            driver_name = self.connections[connection_name].driver_name
+            connection = self.connections[connection_name]
         else:
-            raise Exception("Unknown driver, %s, for connection %s"
-                            % (con_config['driver'], con_name))
+            # In some cases a driver may not be related to a connection. For
+            # example, the 'timer' or 'zuul' triggers.
+            driver_name = connection_name
+            connection = None
+        driver = drivers[dtype][driver_name].split(':')
+        driver_instance = getattr(
+            __import__(driver[0], fromlist=['']), driver[1])(
+                driver_config, self.sched, connection
+        )
 
-    # If the [gerrit] or [smtp] sections still exist, load them in as a
-    # connection named 'gerrit' or 'smtp' respectfully
+        return driver_instance
 
-    if 'gerrit' in config.sections():
-        connections['gerrit'] = \
-            zuul.connection.gerrit.GerritConnection(
-                '_legacy_gerrit', dict(config.items('gerrit')))
+    def getSource(self, connection_name):
+        return self._getDriver('source', connection_name)
 
-    if 'smtp' in config.sections():
-        connections['smtp'] = \
-            zuul.connection.smtp.SMTPConnection(
-                '_legacy_smtp', dict(config.items('smtp')))
+    def getReporter(self, connection_name, driver_config={}):
+        return self._getDriver('reporter', connection_name, driver_config)
 
-    return connections
+    def getTrigger(self, connection_name, driver_config={}):
+        return self._getDriver('trigger', connection_name, driver_config)
diff --git a/zuul/manager/__init__.py b/zuul/manager/__init__.py
new file mode 100644
index 0000000..00e949b
--- /dev/null
+++ b/zuul/manager/__init__.py
@@ -0,0 +1,773 @@
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import extras
+import logging
+
+from zuul import exceptions
+from zuul.model import NullChange
+
+statsd = extras.try_import('statsd.statsd')
+
+
+class DynamicChangeQueueContextManager(object):
+    def __init__(self, change_queue):
+        self.change_queue = change_queue
+
+    def __enter__(self):
+        return self.change_queue
+
+    def __exit__(self, etype, value, tb):
+        if self.change_queue and not self.change_queue.queue:
+            self.change_queue.pipeline.removeQueue(self.change_queue)
+
+
+class StaticChangeQueueContextManager(object):
+    def __init__(self, change_queue):
+        self.change_queue = change_queue
+
+    def __enter__(self):
+        return self.change_queue
+
+    def __exit__(self, etype, value, tb):
+        pass
+
+
+class BasePipelineManager(object):
+    log = logging.getLogger("zuul.BasePipelineManager")
+
+    def __init__(self, sched, pipeline):
+        self.sched = sched
+        self.pipeline = pipeline
+        self.event_filters = []
+        self.changeish_filters = []
+
+    def __str__(self):
+        return "<%s %s>" % (self.__class__.__name__, self.pipeline.name)
+
+    def _postConfig(self, layout):
+        self.log.info("Configured Pipeline Manager %s" % self.pipeline.name)
+        self.log.info("  Source: %s" % self.pipeline.source)
+        self.log.info("  Requirements:")
+        for f in self.changeish_filters:
+            self.log.info("    %s" % f)
+        self.log.info("  Events:")
+        for e in self.event_filters:
+            self.log.info("    %s" % e)
+        self.log.info("  Projects:")
+
+        def log_jobs(tree, indent=0):
+            istr = '    ' + ' ' * indent
+            if tree.job:
+                efilters = ''
+                for b in tree.job._branches:
+                    efilters += str(b)
+                for f in tree.job._files:
+                    efilters += str(f)
+                if tree.job.skip_if_matcher:
+                    efilters += str(tree.job.skip_if_matcher)
+                if efilters:
+                    efilters = ' ' + efilters
+                hold = ''
+                if tree.job.hold_following_changes:
+                    hold = ' [hold]'
+                voting = ''
+                if not tree.job.voting:
+                    voting = ' [nonvoting]'
+                self.log.info("%s%s%s%s%s" % (istr, repr(tree.job),
+                                              efilters, hold, voting))
+            for x in tree.job_trees:
+                log_jobs(x, indent + 2)
+
+        for p in layout.projects.values():
+            tree = self.pipeline.getJobTree(p)
+            if tree:
+                self.log.info("    %s" % p)
+                log_jobs(tree)
+        self.log.info("  On start:")
+        self.log.info("    %s" % self.pipeline.start_actions)
+        self.log.info("  On success:")
+        self.log.info("    %s" % self.pipeline.success_actions)
+        self.log.info("  On failure:")
+        self.log.info("    %s" % self.pipeline.failure_actions)
+        self.log.info("  On merge-failure:")
+        self.log.info("    %s" % self.pipeline.merge_failure_actions)
+        self.log.info("  When disabled:")
+        self.log.info("    %s" % self.pipeline.disabled_actions)
+
+    def getSubmitAllowNeeds(self):
+        # Get a list of code review labels that are allowed to be
+        # "needed" in the submit records for a change, with respect
+        # to this queue.  In other words, the list of review labels
+        # this queue itself is likely to set before submitting.
+        allow_needs = set()
+        for action_reporter in self.pipeline.success_actions:
+            allow_needs.update(action_reporter.getSubmitAllowNeeds())
+        return allow_needs
+
+    def eventMatches(self, event, change):
+        if event.forced_pipeline:
+            if event.forced_pipeline == self.pipeline.name:
+                self.log.debug("Event %s for change %s was directly assigned "
+                               "to pipeline %s" % (event, change, self))
+                return True
+            else:
+                return False
+        for ef in self.event_filters:
+            if ef.matches(event, change):
+                self.log.debug("Event %s for change %s matched %s "
+                               "in pipeline %s" % (event, change, ef, self))
+                return True
+        return False
+
+    def isChangeAlreadyInPipeline(self, change):
+        # Checks live items in the pipeline
+        for item in self.pipeline.getAllItems():
+            if item.live and change.equals(item.change):
+                return True
+        return False
+
+    def isChangeAlreadyInQueue(self, change, change_queue):
+        # Checks any item in the specified change queue
+        for item in change_queue.queue:
+            if change.equals(item.change):
+                return True
+        return False
+
+    def reportStart(self, item):
+        if not self.pipeline._disabled:
+            try:
+                self.log.info("Reporting start, action %s item %s" %
+                              (self.pipeline.start_actions, item))
+                ret = self.sendReport(self.pipeline.start_actions,
+                                      self.pipeline.source, item)
+                if ret:
+                    self.log.error("Reporting item start %s received: %s" %
+                                   (item, ret))
+            except:
+                self.log.exception("Exception while reporting start:")
+
+    def sendReport(self, action_reporters, source, item,
+                   message=None):
+        """Sends the built message off to configured reporters.
+
+        Takes the action_reporters, item, message and extra options and
+        sends them to the pluggable reporters.
+        """
+        report_errors = []
+        if len(action_reporters) > 0:
+            for reporter in action_reporters:
+                ret = reporter.report(source, self.pipeline, item)
+                if ret:
+                    report_errors.append(ret)
+            if len(report_errors) == 0:
+                return
+        return report_errors
+
+    def isChangeReadyToBeEnqueued(self, change):
+        return True
+
+    def enqueueChangesAhead(self, change, quiet, ignore_requirements,
+                            change_queue):
+        return True
+
+    def enqueueChangesBehind(self, change, quiet, ignore_requirements,
+                             change_queue):
+        return True
+
+    def checkForChangesNeededBy(self, change, change_queue):
+        return True
+
+    def getFailingDependentItems(self, item):
+        return None
+
+    def getDependentItems(self, item):
+        orig_item = item
+        items = []
+        while item.item_ahead:
+            items.append(item.item_ahead)
+            item = item.item_ahead
+        self.log.info("Change %s depends on changes %s" %
+                      (orig_item.change,
+                       [x.change for x in items]))
+        return items
+
+    def getItemForChange(self, change):
+        for item in self.pipeline.getAllItems():
+            if item.change.equals(change):
+                return item
+        return None
+
+    def findOldVersionOfChangeAlreadyInQueue(self, change):
+        for item in self.pipeline.getAllItems():
+            if not item.live:
+                continue
+            if change.isUpdateOf(item.change):
+                return item
+        return None
+
+    def removeOldVersionsOfChange(self, change):
+        if not self.pipeline.dequeue_on_new_patchset:
+            return
+        old_item = self.findOldVersionOfChangeAlreadyInQueue(change)
+        if old_item:
+            self.log.debug("Change %s is a new version of %s, removing %s" %
+                           (change, old_item.change, old_item))
+            self.removeItem(old_item)
+
+    def removeAbandonedChange(self, change):
+        self.log.debug("Change %s abandoned, removing." % change)
+        for item in self.pipeline.getAllItems():
+            if not item.live:
+                continue
+            if item.change.equals(change):
+                self.removeItem(item)
+
+    def reEnqueueItem(self, item, last_head):
+        with self.getChangeQueue(item.change, last_head.queue) as change_queue:
+            if change_queue:
+                self.log.debug("Re-enqueing change %s in queue %s" %
+                               (item.change, change_queue))
+                change_queue.enqueueItem(item)
+
+                # Re-set build results in case any new jobs have been
+                # added to the tree.
+                for build in item.current_build_set.getBuilds():
+                    if build.result:
+                        self.pipeline.setResult(item, build)
+                # Similarly, reset the item state.
+                if item.current_build_set.unable_to_merge:
+                    self.pipeline.setUnableToMerge(item)
+                if item.dequeued_needing_change:
+                    self.pipeline.setDequeuedNeedingChange(item)
+
+                self.reportStats(item)
+                return True
+            else:
+                self.log.error("Unable to find change queue for project %s" %
+                               item.change.project)
+                return False
+
+    def addChange(self, change, quiet=False, enqueue_time=None,
+                  ignore_requirements=False, live=True,
+                  change_queue=None):
+        self.log.debug("Considering adding change %s" % change)
+
+        # If we are adding a live change, check if it's a live item
+        # anywhere in the pipeline.  Otherwise, we will perform the
+        # duplicate check below on the specific change_queue.
+        if live and self.isChangeAlreadyInPipeline(change):
+            self.log.debug("Change %s is already in pipeline, "
+                           "ignoring" % change)
+            return True
+
+        if not self.isChangeReadyToBeEnqueued(change):
+            self.log.debug("Change %s is not ready to be enqueued, ignoring" %
+                           change)
+            return False
+
+        if not ignore_requirements:
+            for f in self.changeish_filters:
+                if not f.matches(change):
+                    self.log.debug("Change %s does not match pipeline "
+                                   "requirement %s" % (change, f))
+                    return False
+
+        with self.getChangeQueue(change, change_queue) as change_queue:
+            if not change_queue:
+                self.log.debug("Unable to find change queue for "
+                               "change %s in project %s" %
+                               (change, change.project))
+                return False
+
+            if not self.enqueueChangesAhead(change, quiet, ignore_requirements,
+                                            change_queue):
+                self.log.debug("Failed to enqueue changes "
+                               "ahead of %s" % change)
+                return False
+
+            if self.isChangeAlreadyInQueue(change, change_queue):
+                self.log.debug("Change %s is already in queue, "
+                               "ignoring" % change)
+                return True
+
+            self.log.debug("Adding change %s to queue %s" %
+                           (change, change_queue))
+            item = change_queue.enqueueChange(change)
+            if enqueue_time:
+                item.enqueue_time = enqueue_time
+            item.live = live
+            self.reportStats(item)
+            if not quiet:
+                if len(self.pipeline.start_actions) > 0:
+                    self.reportStart(item)
+            self.enqueueChangesBehind(change, quiet, ignore_requirements,
+                                      change_queue)
+            for trigger in self.sched.triggers.values():
+                trigger.onChangeEnqueued(item.change, self.pipeline)
+            return True
+
+    def dequeueItem(self, item):
+        self.log.debug("Removing change %s from queue" % item.change)
+        item.queue.dequeueItem(item)
+
+    def removeItem(self, item):
+        # Remove an item from the queue, probably because it has been
+        # superseded by another change.
+        self.log.debug("Canceling builds behind change: %s "
+                       "because it is being removed." % item.change)
+        self.cancelJobs(item)
+        self.dequeueItem(item)
+        self.reportStats(item)
+
+    def _makeMergerItem(self, item):
+        # Create a dictionary with all info about the item needed by
+        # the merger.
+        number = None
+        patchset = None
+        oldrev = None
+        newrev = None
+        if hasattr(item.change, 'number'):
+            number = item.change.number
+            patchset = item.change.patchset
+        elif hasattr(item.change, 'newrev'):
+            oldrev = item.change.oldrev
+            newrev = item.change.newrev
+        connection_name = self.pipeline.source.connection.connection_name
+        return dict(project=item.change.project.name,
+                    url=self.pipeline.source.getGitUrl(
+                        item.change.project),
+                    connection_name=connection_name,
+                    merge_mode=item.change.project.merge_mode,
+                    refspec=item.change.refspec,
+                    branch=item.change.branch,
+                    ref=item.current_build_set.ref,
+                    number=number,
+                    patchset=patchset,
+                    oldrev=oldrev,
+                    newrev=newrev,
+                    )
+
+    def prepareRef(self, item):
+        # Returns True if the ref is ready, false otherwise
+        build_set = item.current_build_set
+        if build_set.merge_state == build_set.COMPLETE:
+            return True
+        if build_set.merge_state == build_set.PENDING:
+            return False
+        build_set.merge_state = build_set.PENDING
+        ref = build_set.ref
+        if hasattr(item.change, 'refspec') and not ref:
+            self.log.debug("Preparing ref for: %s" % item.change)
+            item.current_build_set.setConfiguration()
+            dependent_items = self.getDependentItems(item)
+            dependent_items.reverse()
+            all_items = dependent_items + [item]
+            merger_items = map(self._makeMergerItem, all_items)
+            self.sched.merger.mergeChanges(merger_items,
+                                           item.current_build_set,
+                                           self.pipeline.precedence)
+        else:
+            self.log.debug("Preparing update repo for: %s" % item.change)
+            url = self.pipeline.source.getGitUrl(item.change.project)
+            self.sched.merger.updateRepo(item.change.project.name,
+                                         url, build_set,
+                                         self.pipeline.precedence)
+        return False
+
+    def _launchJobs(self, item, jobs):
+        self.log.debug("Launching jobs for change %s" % item.change)
+        dependent_items = self.getDependentItems(item)
+        for job in jobs:
+            self.log.debug("Found job %s for change %s" % (job, item.change))
+            try:
+                build = self.sched.launcher.launch(job, item,
+                                                   self.pipeline,
+                                                   dependent_items)
+                self.log.debug("Adding build %s of job %s to item %s" %
+                               (build, job, item))
+                item.addBuild(build)
+            except:
+                self.log.exception("Exception while launching job %s "
+                                   "for change %s:" % (job, item.change))
+
+    def launchJobs(self, item):
+        # TODO(jeblair): This should return a value indicating a job
+        # was launched.  Appears to be a longstanding bug.
+        jobs = self.pipeline.findJobsToRun(item)
+        if jobs:
+            self._launchJobs(item, jobs)
+
+    def cancelJobs(self, item, prime=True):
+        self.log.debug("Cancel jobs for change %s" % item.change)
+        canceled = False
+        old_build_set = item.current_build_set
+        if prime and item.current_build_set.ref:
+            item.resetAllBuilds()
+        for build in old_build_set.getBuilds():
+            try:
+                self.sched.launcher.cancel(build)
+            except:
+                self.log.exception("Exception while canceling build %s "
+                                   "for change %s" % (build, item.change))
+            build.result = 'CANCELED'
+            canceled = True
+        self.updateBuildDescriptions(old_build_set)
+        for item_behind in item.items_behind:
+            self.log.debug("Canceling jobs for change %s, behind change %s" %
+                           (item_behind.change, item.change))
+            if self.cancelJobs(item_behind, prime=prime):
+                canceled = True
+        return canceled
+
+    def _processOneItem(self, item, nnfi):
+        changed = False
+        item_ahead = item.item_ahead
+        if item_ahead and (not item_ahead.live):
+            item_ahead = None
+        change_queue = item.queue
+        failing_reasons = []  # Reasons this item is failing
+
+        if self.checkForChangesNeededBy(item.change, change_queue) is not True:
+            # It's not okay to enqueue this change, we should remove it.
+            self.log.info("Dequeuing change %s because "
+                          "it can no longer merge" % item.change)
+            self.cancelJobs(item)
+            self.dequeueItem(item)
+            self.pipeline.setDequeuedNeedingChange(item)
+            if item.live:
+                try:
+                    self.reportItem(item)
+                except exceptions.MergeFailure:
+                    pass
+            return (True, nnfi)
+        dep_items = self.getFailingDependentItems(item)
+        actionable = change_queue.isActionable(item)
+        item.active = actionable
+        ready = False
+        if dep_items:
+            failing_reasons.append('a needed change is failing')
+            self.cancelJobs(item, prime=False)
+        else:
+            item_ahead_merged = False
+            if (item_ahead and item_ahead.change.is_merged):
+                item_ahead_merged = True
+            if (item_ahead != nnfi and not item_ahead_merged):
+                # Our current base is different than what we expected,
+                # and it's not because our current base merged.  Something
+                # ahead must have failed.
+                self.log.info("Resetting builds for change %s because the "
+                              "item ahead, %s, is not the nearest non-failing "
+                              "item, %s" % (item.change, item_ahead, nnfi))
+                change_queue.moveItem(item, nnfi)
+                changed = True
+                self.cancelJobs(item)
+            if actionable:
+                ready = self.prepareRef(item)
+                if item.current_build_set.unable_to_merge:
+                    failing_reasons.append("it has a merge conflict")
+                    ready = False
+        if actionable and ready and self.launchJobs(item):
+            changed = True
+        if self.pipeline.didAnyJobFail(item):
+            failing_reasons.append("at least one job failed")
+        if (not item.live) and (not item.items_behind):
+            failing_reasons.append("is a non-live item with no items behind")
+            self.dequeueItem(item)
+            changed = True
+        if ((not item_ahead) and self.pipeline.areAllJobsComplete(item)
+            and item.live):
+            try:
+                self.reportItem(item)
+            except exceptions.MergeFailure:
+                failing_reasons.append("it did not merge")
+                for item_behind in item.items_behind:
+                    self.log.info("Resetting builds for change %s because the "
+                                  "item ahead, %s, failed to merge" %
+                                  (item_behind.change, item))
+                    self.cancelJobs(item_behind)
+            self.dequeueItem(item)
+            changed = True
+        elif not failing_reasons and item.live:
+            nnfi = item
+        item.current_build_set.failing_reasons = failing_reasons
+        if failing_reasons:
+            self.log.debug("%s is a failing item because %s" %
+                           (item, failing_reasons))
+        return (changed, nnfi)
+
+    def processQueue(self):
+        # Do whatever needs to be done for each change in the queue
+        self.log.debug("Starting queue processor: %s" % self.pipeline.name)
+        changed = False
+        for queue in self.pipeline.queues:
+            queue_changed = False
+            nnfi = None  # Nearest non-failing item
+            for item in queue.queue[:]:
+                item_changed, nnfi = self._processOneItem(
+                    item, nnfi)
+                if item_changed:
+                    queue_changed = True
+                self.reportStats(item)
+            if queue_changed:
+                changed = True
+                status = ''
+                for item in queue.queue:
+                    status += item.formatStatus()
+                if status:
+                    self.log.debug("Queue %s status is now:\n %s" %
+                                   (queue.name, status))
+        self.log.debug("Finished queue processor: %s (changed: %s)" %
+                       (self.pipeline.name, changed))
+        return changed
+
+    def updateBuildDescriptions(self, build_set):
+        for build in build_set.getBuilds():
+            desc = self.formatDescription(build)
+            self.sched.launcher.setBuildDescription(build, desc)
+
+        if build_set.previous_build_set:
+            for build in build_set.previous_build_set.getBuilds():
+                desc = self.formatDescription(build)
+                self.sched.launcher.setBuildDescription(build, desc)
+
+    def onBuildStarted(self, build):
+        self.log.debug("Build %s started" % build)
+        return True
+
+    def onBuildCompleted(self, build):
+        self.log.debug("Build %s completed" % build)
+        item = build.build_set.item
+
+        self.pipeline.setResult(item, build)
+        self.log.debug("Item %s status is now:\n %s" %
+                       (item, item.formatStatus()))
+        return True
+
+    def onMergeCompleted(self, event):
+        build_set = event.build_set
+        item = build_set.item
+        build_set.merge_state = build_set.COMPLETE
+        build_set.zuul_url = event.zuul_url
+        if event.merged:
+            build_set.commit = event.commit
+        elif event.updated:
+            if not isinstance(item, NullChange):
+                build_set.commit = item.change.newrev
+        if not build_set.commit:
+            self.log.info("Unable to merge change %s" % item.change)
+            self.pipeline.setUnableToMerge(item)
+
+    def reportItem(self, item):
+        if not item.reported:
+            # _reportItem() returns True if it failed to report.
+            item.reported = not self._reportItem(item)
+        if self.changes_merge:
+            succeeded = self.pipeline.didAllJobsSucceed(item)
+            merged = item.reported
+            if merged:
+                merged = self.pipeline.source.isMerged(item.change,
+                                                       item.change.branch)
+            self.log.info("Reported change %s status: all-succeeded: %s, "
+                          "merged: %s" % (item.change, succeeded, merged))
+            change_queue = item.queue
+            if not (succeeded and merged):
+                self.log.debug("Reported change %s failed tests or failed "
+                               "to merge" % (item.change))
+                change_queue.decreaseWindowSize()
+                self.log.debug("%s window size decreased to %s" %
+                               (change_queue, change_queue.window))
+                raise exceptions.MergeFailure(
+                    "Change %s failed to merge" % item.change)
+            else:
+                change_queue.increaseWindowSize()
+                self.log.debug("%s window size increased to %s" %
+                               (change_queue, change_queue.window))
+
+                for trigger in self.sched.triggers.values():
+                    trigger.onChangeMerged(item.change, self.pipeline.source)
+
+    def _reportItem(self, item):
+        self.log.debug("Reporting change %s" % item.change)
+        ret = True  # Means error as returned by trigger.report
+        if not self.pipeline.getJobs(item):
+            # We don't send empty reports with +1,
+            # and the same for -1's (merge failures or transient errors)
+            # as they cannot be followed by +1's
+            self.log.debug("No jobs for change %s" % item.change)
+            actions = []
+        elif self.pipeline.didAllJobsSucceed(item):
+            self.log.debug("success %s" % (self.pipeline.success_actions))
+            actions = self.pipeline.success_actions
+            item.setReportedResult('SUCCESS')
+            self.pipeline._consecutive_failures = 0
+        elif not self.pipeline.didMergerSucceed(item):
+            actions = self.pipeline.merge_failure_actions
+            item.setReportedResult('MERGER_FAILURE')
+        else:
+            actions = self.pipeline.failure_actions
+            item.setReportedResult('FAILURE')
+            self.pipeline._consecutive_failures += 1
+        if self.pipeline._disabled:
+            actions = self.pipeline.disabled_actions
+        # Check here if we should disable so that we only use the disabled
+        # reporters /after/ the last disable_at failure is still reported as
+        # normal.
+        if (self.pipeline.disable_at and not self.pipeline._disabled and
+            self.pipeline._consecutive_failures >= self.pipeline.disable_at):
+            self.pipeline._disabled = True
+        if actions:
+            try:
+                self.log.info("Reporting item %s, actions: %s" %
+                              (item, actions))
+                ret = self.sendReport(actions, self.pipeline.source, item)
+                if ret:
+                    self.log.error("Reporting item %s received: %s" %
+                                   (item, ret))
+            except:
+                self.log.exception("Exception while reporting:")
+                item.setReportedResult('ERROR')
+        self.updateBuildDescriptions(item.current_build_set)
+        return ret
+
+    def formatDescription(self, build):
+        concurrent_changes = ''
+        concurrent_builds = ''
+        other_builds = ''
+
+        for change in build.build_set.other_changes:
+            concurrent_changes += '<li><a href="{change.url}">\
+              {change.number},{change.patchset}</a></li>'.format(
+                change=change)
+
+        change = build.build_set.item.change
+
+        for build in build.build_set.getBuilds():
+            if build.url:
+                concurrent_builds += """\
+<li>
+  <a href="{build.url}">
+  {build.job.name} #{build.number}</a>: {build.result}
+</li>
+""".format(build=build)
+            else:
+                concurrent_builds += """\
+<li>
+  {build.job.name}: {build.result}
+</li>""".format(build=build)
+
+        if build.build_set.previous_build_set:
+            other_build = build.build_set.previous_build_set.getBuild(
+                build.job.name)
+            if other_build:
+                other_builds += """\
+<li>
+  Preceded by: <a href="{build.url}">
+  {build.job.name} #{build.number}</a>
+</li>
+""".format(build=other_build)
+
+        if build.build_set.next_build_set:
+            other_build = build.build_set.next_build_set.getBuild(
+                build.job.name)
+            if other_build:
+                other_builds += """\
+<li>
+  Succeeded by: <a href="{build.url}">
+  {build.job.name} #{build.number}</a>
+</li>
+""".format(build=other_build)
+
+        result = build.build_set.result
+
+        if hasattr(change, 'number'):
+            ret = """\
+<p>
+  Triggered by change:
+    <a href="{change.url}">{change.number},{change.patchset}</a><br/>
+  Branch: <b>{change.branch}</b><br/>
+  Pipeline: <b>{self.pipeline.name}</b>
+</p>"""
+        elif hasattr(change, 'ref'):
+            ret = """\
+<p>
+  Triggered by reference:
+    {change.ref}</a><br/>
+  Old revision: <b>{change.oldrev}</b><br/>
+  New revision: <b>{change.newrev}</b><br/>
+  Pipeline: <b>{self.pipeline.name}</b>
+</p>"""
+        else:
+            ret = ""
+
+        if concurrent_changes:
+            ret += """\
+<p>
+  Other changes tested concurrently with this change:
+  <ul>{concurrent_changes}</ul>
+</p>
+"""
+        if concurrent_builds:
+            ret += """\
+<p>
+  All builds for this change set:
+  <ul>{concurrent_builds}</ul>
+</p>
+"""
+
+        if other_builds:
+            ret += """\
+<p>
+  Other build sets for this change:
+  <ul>{other_builds}</ul>
+</p>
+"""
+        if result:
+            ret += """\
+<p>
+  Reported result: <b>{result}</b>
+</p>
+"""
+
+        ret = ret.format(**locals())
+        return ret
+
+    def reportStats(self, item):
+        if not statsd:
+            return
+        try:
+            # Update the gauge on enqueue and dequeue, but timers only
+            # when dequeing.
+            if item.dequeue_time:
+                dt = int((item.dequeue_time - item.enqueue_time) * 1000)
+            else:
+                dt = None
+            items = len(self.pipeline.getAllItems())
+
+            # stats.timers.zuul.pipeline.NAME.resident_time
+            # stats_counts.zuul.pipeline.NAME.total_changes
+            # stats.gauges.zuul.pipeline.NAME.current_changes
+            key = 'zuul.pipeline.%s' % self.pipeline.name
+            statsd.gauge(key + '.current_changes', items)
+            if dt:
+                statsd.timing(key + '.resident_time', dt)
+                statsd.incr(key + '.total_changes')
+
+            # stats.timers.zuul.pipeline.NAME.ORG.PROJECT.resident_time
+            # stats_counts.zuul.pipeline.NAME.ORG.PROJECT.total_changes
+            project_name = item.change.project.name.replace('/', '.')
+            key += '.%s' % project_name
+            if dt:
+                statsd.timing(key + '.resident_time', dt)
+                statsd.incr(key + '.total_changes')
+        except:
+            self.log.exception("Exception reporting pipeline stats")
diff --git a/zuul/manager/dependent.py b/zuul/manager/dependent.py
new file mode 100644
index 0000000..02dc9f6
--- /dev/null
+++ b/zuul/manager/dependent.py
@@ -0,0 +1,198 @@
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import logging
+
+from zuul import model
+from zuul.manager import BasePipelineManager, StaticChangeQueueContextManager
+
+
+class DependentPipelineManager(BasePipelineManager):
+    log = logging.getLogger("zuul.DependentPipelineManager")
+    changes_merge = True
+
+    def __init__(self, *args, **kwargs):
+        super(DependentPipelineManager, self).__init__(*args, **kwargs)
+
+    def _postConfig(self, layout):
+        super(DependentPipelineManager, self)._postConfig(layout)
+        self.buildChangeQueues()
+
+    def buildChangeQueues(self):
+        self.log.debug("Building shared change queues")
+        change_queues = []
+
+        for project in self.pipeline.getProjects():
+            change_queue = model.ChangeQueue(
+                self.pipeline,
+                window=self.pipeline.window,
+                window_floor=self.pipeline.window_floor,
+                window_increase_type=self.pipeline.window_increase_type,
+                window_increase_factor=self.pipeline.window_increase_factor,
+                window_decrease_type=self.pipeline.window_decrease_type,
+                window_decrease_factor=self.pipeline.window_decrease_factor)
+            change_queue.addProject(project)
+            change_queues.append(change_queue)
+            self.log.debug("Created queue: %s" % change_queue)
+
+        # Iterate over all queues trying to combine them, and keep doing
+        # so until they can not be combined further.
+        last_change_queues = change_queues
+        while True:
+            new_change_queues = self.combineChangeQueues(last_change_queues)
+            if len(last_change_queues) == len(new_change_queues):
+                break
+            last_change_queues = new_change_queues
+
+        self.log.info("  Shared change queues:")
+        for queue in new_change_queues:
+            self.pipeline.addQueue(queue)
+            self.log.info("    %s containing %s" % (
+                queue, queue.generated_name))
+
+    def combineChangeQueues(self, change_queues):
+        self.log.debug("Combining shared queues")
+        new_change_queues = []
+        for a in change_queues:
+            merged_a = False
+            for b in new_change_queues:
+                if not a.getJobs().isdisjoint(b.getJobs()):
+                    self.log.debug("Merging queue %s into %s" % (a, b))
+                    b.mergeChangeQueue(a)
+                    merged_a = True
+                    break  # this breaks out of 'for b' and continues 'for a'
+            if not merged_a:
+                self.log.debug("Keeping queue %s" % (a))
+                new_change_queues.append(a)
+        return new_change_queues
+
+    def getChangeQueue(self, change, existing=None):
+        if existing:
+            return StaticChangeQueueContextManager(existing)
+        return StaticChangeQueueContextManager(
+            self.pipeline.getQueue(change.project))
+
+    def isChangeReadyToBeEnqueued(self, change):
+        if not self.pipeline.source.canMerge(change,
+                                             self.getSubmitAllowNeeds()):
+            self.log.debug("Change %s can not merge, ignoring" % change)
+            return False
+        return True
+
+    def enqueueChangesBehind(self, change, quiet, ignore_requirements,
+                             change_queue):
+        to_enqueue = []
+        self.log.debug("Checking for changes needing %s:" % change)
+        if not hasattr(change, 'needed_by_changes'):
+            self.log.debug("  Changeish does not support dependencies")
+            return
+        for other_change in change.needed_by_changes:
+            with self.getChangeQueue(other_change) as other_change_queue:
+                if other_change_queue != change_queue:
+                    self.log.debug("  Change %s in project %s can not be "
+                                   "enqueued in the target queue %s" %
+                                   (other_change, other_change.project,
+                                    change_queue))
+                    continue
+            if self.pipeline.source.canMerge(other_change,
+                                             self.getSubmitAllowNeeds()):
+                self.log.debug("  Change %s needs %s and is ready to merge" %
+                               (other_change, change))
+                to_enqueue.append(other_change)
+
+        if not to_enqueue:
+            self.log.debug("  No changes need %s" % change)
+
+        for other_change in to_enqueue:
+            self.addChange(other_change, quiet=quiet,
+                           ignore_requirements=ignore_requirements,
+                           change_queue=change_queue)
+
+    def enqueueChangesAhead(self, change, quiet, ignore_requirements,
+                            change_queue):
+        ret = self.checkForChangesNeededBy(change, change_queue)
+        if ret in [True, False]:
+            return ret
+        self.log.debug("  Changes %s must be merged ahead of %s" %
+                       (ret, change))
+        for needed_change in ret:
+            r = self.addChange(needed_change, quiet=quiet,
+                               ignore_requirements=ignore_requirements,
+                               change_queue=change_queue)
+            if not r:
+                return False
+        return True
+
+    def checkForChangesNeededBy(self, change, change_queue):
+        self.log.debug("Checking for changes needed by %s:" % change)
+        # Return true if okay to proceed enqueing this change,
+        # false if the change should not be enqueued.
+        if not hasattr(change, 'needs_changes'):
+            self.log.debug("  Changeish does not support dependencies")
+            return True
+        if not change.needs_changes:
+            self.log.debug("  No changes needed")
+            return True
+        changes_needed = []
+        # Ignore supplied change_queue
+        with self.getChangeQueue(change) as change_queue:
+            for needed_change in change.needs_changes:
+                self.log.debug("  Change %s needs change %s:" % (
+                    change, needed_change))
+                if needed_change.is_merged:
+                    self.log.debug("  Needed change is merged")
+                    continue
+                with self.getChangeQueue(needed_change) as needed_change_queue:
+                    if needed_change_queue != change_queue:
+                        self.log.debug("  Change %s in project %s does not "
+                                       "share a change queue with %s "
+                                       "in project %s" %
+                                       (needed_change, needed_change.project,
+                                        change, change.project))
+                        return False
+                if not needed_change.is_current_patchset:
+                    self.log.debug("  Needed change is not the "
+                                   "current patchset")
+                    return False
+                if self.isChangeAlreadyInQueue(needed_change, change_queue):
+                    self.log.debug("  Needed change is already ahead "
+                                   "in the queue")
+                    continue
+                if self.pipeline.source.canMerge(needed_change,
+                                                 self.getSubmitAllowNeeds()):
+                    self.log.debug("  Change %s is needed" % needed_change)
+                    if needed_change not in changes_needed:
+                        changes_needed.append(needed_change)
+                        continue
+                # The needed change can't be merged.
+                self.log.debug("  Change %s is needed but can not be merged" %
+                               needed_change)
+                return False
+        if changes_needed:
+            return changes_needed
+        return True
+
+    def getFailingDependentItems(self, item):
+        if not hasattr(item.change, 'needs_changes'):
+            return None
+        if not item.change.needs_changes:
+            return None
+        failing_items = set()
+        for needed_change in item.change.needs_changes:
+            needed_item = self.getItemForChange(needed_change)
+            if not needed_item:
+                continue
+            if needed_item.current_build_set.failing_reasons:
+                failing_items.add(needed_item)
+        if failing_items:
+            return failing_items
+        return None
diff --git a/zuul/manager/independent.py b/zuul/manager/independent.py
new file mode 100644
index 0000000..5690189
--- /dev/null
+++ b/zuul/manager/independent.py
@@ -0,0 +1,95 @@
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import logging
+
+from zuul import model
+from zuul.manager import BasePipelineManager, DynamicChangeQueueContextManager
+
+
+class IndependentPipelineManager(BasePipelineManager):
+    log = logging.getLogger("zuul.IndependentPipelineManager")
+    changes_merge = False
+
+    def _postConfig(self, layout):
+        super(IndependentPipelineManager, self)._postConfig(layout)
+
+    def getChangeQueue(self, change, existing=None):
+        # creates a new change queue for every change
+        if existing:
+            return DynamicChangeQueueContextManager(existing)
+        if change.project not in self.pipeline.getProjects():
+            self.pipeline.addProject(change.project)
+        change_queue = model.ChangeQueue(self.pipeline)
+        change_queue.addProject(change.project)
+        self.pipeline.addQueue(change_queue)
+        self.log.debug("Dynamically created queue %s", change_queue)
+        return DynamicChangeQueueContextManager(change_queue)
+
+    def enqueueChangesAhead(self, change, quiet, ignore_requirements,
+                            change_queue):
+        ret = self.checkForChangesNeededBy(change, change_queue)
+        if ret in [True, False]:
+            return ret
+        self.log.debug("  Changes %s must be merged ahead of %s" %
+                       (ret, change))
+        for needed_change in ret:
+            # This differs from the dependent pipeline by enqueuing
+            # changes ahead as "not live", that is, not intended to
+            # have jobs run.  Also, pipeline requirements are always
+            # ignored (which is safe because the changes are not
+            # live).
+            r = self.addChange(needed_change, quiet=True,
+                               ignore_requirements=True,
+                               live=False, change_queue=change_queue)
+            if not r:
+                return False
+        return True
+
+    def checkForChangesNeededBy(self, change, change_queue):
+        if self.pipeline.ignore_dependencies:
+            return True
+        self.log.debug("Checking for changes needed by %s:" % change)
+        # Return true if okay to proceed enqueing this change,
+        # false if the change should not be enqueued.
+        if not hasattr(change, 'needs_changes'):
+            self.log.debug("  Changeish does not support dependencies")
+            return True
+        if not change.needs_changes:
+            self.log.debug("  No changes needed")
+            return True
+        changes_needed = []
+        for needed_change in change.needs_changes:
+            self.log.debug("  Change %s needs change %s:" % (
+                change, needed_change))
+            if needed_change.is_merged:
+                self.log.debug("  Needed change is merged")
+                continue
+            if self.isChangeAlreadyInQueue(needed_change, change_queue):
+                self.log.debug("  Needed change is already ahead in the queue")
+                continue
+            self.log.debug("  Change %s is needed" % needed_change)
+            if needed_change not in changes_needed:
+                changes_needed.append(needed_change)
+                continue
+            # This differs from the dependent pipeline check in not
+            # verifying that the dependent change is mergable.
+        if changes_needed:
+            return changes_needed
+        return True
+
+    def dequeueItem(self, item):
+        super(IndependentPipelineManager, self).dequeueItem(item)
+        # An independent pipeline manager dynamically removes empty
+        # queues
+        if not item.queue.queue:
+            self.pipeline.removeQueue(item.queue)
diff --git a/zuul/merger/merger.py b/zuul/merger/merger.py
index b7e1842..eaa5721 100644
--- a/zuul/merger/merger.py
+++ b/zuul/merger/merger.py
@@ -209,7 +209,7 @@
         self.username = username
 
     def _makeSSHWrappers(self, working_root, connections):
-        for connection_name, connection in connections.items():
+        for connection_name, connection in connections.connections.items():
             sshkey = connection.connection_config.get('sshkey')
             if sshkey:
                 self._makeSSHWrapper(sshkey, working_root, connection_name)
diff --git a/zuul/model.py b/zuul/model.py
index 2893d6f..aa21f85 100644
--- a/zuul/model.py
+++ b/zuul/model.py
@@ -67,8 +67,9 @@
 
 class Pipeline(object):
     """A top-level pipeline such as check, gate, post, etc."""
-    def __init__(self, name):
+    def __init__(self, name, layout):
         self.name = name
+        self.layout = layout
         self.description = None
         self.failure_message = None
         self.merge_failure_message = None
@@ -81,6 +82,7 @@
         self.queues = []
         self.precedence = PRECEDENCE_NORMAL
         self.source = None
+        self.triggers = []
         self.start_actions = []
         self.success_actions = []
         self.failure_actions = []
@@ -96,6 +98,16 @@
         self.window_decrease_type = None
         self.window_decrease_factor = None
 
+    @property
+    def actions(self):
+        return (
+            self.start_actions +
+            self.success_actions +
+            self.failure_actions +
+            self.merge_failure_actions +
+            self.disabled_actions
+        )
+
     def __repr__(self):
         return '<Pipeline %s>' % self.name
 
@@ -136,11 +148,6 @@
 
     def _findJobsToRun(self, job_trees, item):
         torun = []
-        if item.item_ahead:
-            # Only run jobs if any 'hold' jobs on the change ahead
-            # have completed successfully.
-            if self.isHoldingFollowingChanges(item.item_ahead):
-                return []
         for tree in job_trees:
             job = tree.job
             result = None
@@ -163,7 +170,7 @@
     def findJobsToRun(self, item):
         if not item.live:
             return []
-        tree = self.getJobTree(item.change.project)
+        tree = item.job_tree
         if not tree:
             return []
         return self._findJobsToRun(tree.job_trees, item)
@@ -324,24 +331,15 @@
     def addProject(self, project):
         if project not in self.projects:
             self.projects.append(project)
-            self._jobs |= set(self.pipeline.getJobTree(project).getJobs())
 
             names = [x.name for x in self.projects]
             names.sort()
             self.generated_name = ', '.join(names)
-
-            for job in self._jobs:
-                if job.queue_name:
-                    if (self.assigned_name and
-                            job.queue_name != self.assigned_name):
-                        raise Exception("More than one name assigned to "
-                                        "change queue: %s != %s" %
-                                        (self.assigned_name, job.queue_name))
-                    self.assigned_name = job.queue_name
             self.name = self.assigned_name or self.generated_name
 
     def enqueueChange(self, change):
         item = QueueItem(self, change)
+        item.freezeJobTree()
         self.enqueueItem(item)
         item.enqueue_time = time.time()
         return item
@@ -431,51 +429,88 @@
         return '<Project %s>' % (self.name)
 
 
+class Inheritable(object):
+    def __init__(self, parent=None):
+        self.parent = parent
+
+    def __getattribute__(self, name):
+        parent = object.__getattribute__(self, 'parent')
+        try:
+            return object.__getattribute__(self, name)
+        except AttributeError:
+            if parent:
+                return getattr(parent, name)
+            raise
+
+
 class Job(object):
+    attributes = dict(
+        timeout=None,
+        # variables={},
+        # nodes=[],
+        # auth={},
+        workspace=None,
+        pre_run=None,
+        post_run=None,
+        voting=None,
+        failure_message=None,
+        success_message=None,
+        failure_url=None,
+        success_url=None,
+        # Matchers.  These are separate so they can be individually
+        # overidden.
+        branch_matcher=None,
+        file_matcher=None,
+        irrelevant_file_matcher=None,  # skip-if
+        swift=None,  # TODOv3(jeblair): move to auth
+        parameter_function=None,  # TODOv3(jeblair): remove
+        success_pattern=None,  # TODOv3(jeblair): remove
+    )
+
     def __init__(self, name):
         self.name = name
-        self.queue_name = None
-        self.failure_message = None
-        self.success_message = None
-        self.failure_pattern = None
-        self.success_pattern = None
-        self.parameter_function = None
-        self.hold_following_changes = False
-        self.voting = True
-        self.branches = []
-        self._branches = []
-        self.files = []
-        self._files = []
-        self.skip_if_matcher = None
-        self.swift = {}
-        self.parent = None
+        for k, v in self.attributes.items():
+            setattr(self, k, v)
+
+    def __equals__(self, other):
+        # Compare the name and all inheritable attributes to determine
+        # whether two jobs with the same name are identically
+        # configured.  Useful upon reconfiguration.
+        if not isinstance(other, Job):
+            return False
+        if self.name != other.name:
+            return False
+        for k, v in self.attributes.items():
+            if getattr(self, k) != getattr(other, k):
+                return False
+        return True
 
     def __str__(self):
         return self.name
 
     def __repr__(self):
-        return '<Job %s>' % (self.name)
+        return '<Job %s>' % (self.name,)
+
+    def inheritFrom(self, other):
+        """Copy the inheritable attributes which have been set on the other
+        job to this job."""
+
+        if not isinstance(other, Job):
+            raise Exception("Job unable to inherit from %s" % (other,))
+        for k, v in self.attributes.items():
+            if getattr(other, k) != v:
+                setattr(self, k, getattr(other, k))
 
     def changeMatches(self, change):
-        matches_branch = False
-        for branch in self.branches:
-            if hasattr(change, 'branch') and branch.match(change.branch):
-                matches_branch = True
-            if hasattr(change, 'ref') and branch.match(change.ref):
-                matches_branch = True
-        if self.branches and not matches_branch:
+        if self.branch_matcher and not self.branch_matcher.matches(change):
             return False
 
-        matches_file = False
-        for f in self.files:
-            if hasattr(change, 'files'):
-                for cf in change.files:
-                    if f.match(cf):
-                        matches_file = True
-        if self.files and not matches_file:
+        if self.file_matcher and not self.file_matcher.matches(change):
             return False
 
-        if self.skip_if_matcher and self.skip_if_matcher.matches(change):
+        # NB: This is a negative match.
+        if (self.irrelevant_file_matcher and
+            self.irrelevant_file_matcher.matches(change)):
             return False
 
         return True
@@ -648,6 +683,7 @@
         self.reported = False
         self.active = False  # Whether an item is within an active window
         self.live = True  # Whether an item is intended to be processed at all
+        self.job_tree = None
 
     def __repr__(self):
         if self.pipeline:
@@ -675,6 +711,43 @@
     def setReportedResult(self, result):
         self.current_build_set.result = result
 
+    def _createJobTree(self, job_trees, parent):
+        for tree in job_trees:
+            job = tree.job
+            if not job.changeMatches(self.change):
+                continue
+            frozen_job = Job(job.name)
+            frozen_tree = JobTree(frozen_job)
+            inherited = set()
+            for variant in self.pipeline.layout.getJobs(job.name):
+                if variant.changeMatches(self.change):
+                    if variant not in inherited:
+                        frozen_job.inheritFrom(variant)
+                        inherited.add(variant)
+            if job not in inherited:
+                # Only update from the job in the tree if it is
+                # unique, otherwise we might unset an attribute we
+                # have overloaded.
+                frozen_job.inheritFrom(job)
+            parent.job_trees.append(frozen_tree)
+            self._createJobTree(tree.job_trees, frozen_tree)
+
+    def createJobTree(self):
+        project_tree = self.pipeline.getJobTree(self.change.project)
+        ret = JobTree(None)
+        self._createJobTree(project_tree.job_trees, ret)
+        return ret
+
+    def freezeJobTree(self):
+        """Find or create actual matching jobs for this item's change and
+        store the resulting job tree."""
+        self.job_tree = self.createJobTree()
+
+    def getJobs(self):
+        if not self.live or not self.job_tree:
+            return []
+        return self.job_tree.getJobs()
+
     def formatJSON(self):
         changeish = self.change
         ret = {}
@@ -1287,14 +1360,30 @@
     def __init__(self):
         self.projects = {}
         self.pipelines = OrderedDict()
+        # This is a dictionary of name -> [jobs].  The first element
+        # of the list is the first job added with that name.  It is
+        # the reference definition for a given job.  Subsequent
+        # elements are aspects of that job with different matchers
+        # that override some attribute of the job.  These aspects all
+        # inherit from the reference definition.
         self.jobs = {}
 
     def getJob(self, name):
         if name in self.jobs:
-            return self.jobs[name]
-        job = Job(name)
-        self.jobs[name] = job
-        return job
+            return self.jobs[name][0]
+        return None
+
+    def getJobs(self, name):
+        return self.jobs.get(name, [])
+
+    def addJob(self, job):
+        if job.name in self.jobs:
+            self.jobs[job.name].append(job)
+        else:
+            self.jobs[job.name] = [job]
+
+    def addPipeline(self, pipeline):
+        self.pipelines[pipeline.name] = pipeline
 
 
 class Tenant(object):
diff --git a/zuul/scheduler.py b/zuul/scheduler.py
index 979f93e..b60937a 100644
--- a/zuul/scheduler.py
+++ b/zuul/scheduler.py
@@ -21,67 +21,19 @@
 import os
 import pickle
 from six.moves import queue as Queue
-import re
 import sys
 import threading
 import time
-import yaml
 
-import layoutvalidator
+import configloader
 import model
-from model import Pipeline, Project, ChangeQueue
-from model import ChangeishFilter, NullChange
-from zuul import change_matcher, exceptions
+from model import Project
+from zuul import exceptions
 from zuul import version as zuul_version
 
 statsd = extras.try_import('statsd.statsd')
 
 
-def deep_format(obj, paramdict):
-    """Apply the paramdict via str.format() to all string objects found within
-       the supplied obj. Lists and dicts are traversed recursively.
-
-       Borrowed from Jenkins Job Builder project"""
-    if isinstance(obj, str):
-        ret = obj.format(**paramdict)
-    elif isinstance(obj, list):
-        ret = []
-        for item in obj:
-            ret.append(deep_format(item, paramdict))
-    elif isinstance(obj, dict):
-        ret = {}
-        for item in obj:
-            exp_item = item.format(**paramdict)
-
-            ret[exp_item] = deep_format(obj[item], paramdict)
-    else:
-        ret = obj
-    return ret
-
-
-def extend_dict(a, b):
-    """Extend dictionary a (which will be modified in place) with the
-       contents of b.  This is designed for Zuul yaml files which are
-       typically dictionaries of lists of dictionaries, e.g.,
-       {'pipelines': ['name': 'gate']}.  If two such dictionaries each
-       define a pipeline, the result will be a single dictionary with
-       a pipelines entry whose value is a two-element list."""
-
-    for k, v in b.items():
-        if k not in a:
-            a[k] = v
-        elif isinstance(v, dict) and isinstance(a[k], dict):
-            extend_dict(a[k], v)
-        elif isinstance(v, list) and isinstance(a[k], list):
-            a[k] += v
-        elif isinstance(v, list):
-            a[k] = [a[k]] + v
-        elif isinstance(a[k], list):
-            a[k] += [v]
-        else:
-            raise Exception("Unhandled case in extend_dict at %s" % (k,))
-
-
 class ManagementEvent(object):
     """An event that should be processed within the main queue run loop"""
     def __init__(self):
@@ -208,9 +160,8 @@
         self._stopped = False
         self.launcher = None
         self.merger = None
-        self.connections = dict()
-        # These may be very similar to connections
-        self.sources = dict()
+        self.connections = None
+        # TODO(jeblair): fix this
         # Despite triggers being part of the pipeline, there is one trigger set
         # per scheduler. The pipeline handles the trigger filters but since
         # the events are handled by the scheduler itself it needs to handle
@@ -227,15 +178,6 @@
         self.zuul_version = zuul_version.version_info.release_string()
         self.last_reconfigured = None
 
-        # A set of reporter configuration keys to action mapping
-        self._reporter_actions = {
-            'start': 'start_actions',
-            'success': 'success_actions',
-            'failure': 'failure_actions',
-            'merge-failure': 'merge_failure_actions',
-            'disabled': 'disabled_actions',
-        }
-
     def stop(self):
         self._stopped = True
         self.stopConnections()
@@ -246,364 +188,12 @@
         # registerConnections as we don't want to do the onLoad event yet.
         return self._parseConfig(config_path, connections)
 
-    def _parseSkipIf(self, config_job):
-        cm = change_matcher
-        skip_matchers = []
-
-        for config_skip in config_job.get('skip-if', []):
-            nested_matchers = []
-
-            project_regex = config_skip.get('project')
-            if project_regex:
-                nested_matchers.append(cm.ProjectMatcher(project_regex))
-
-            branch_regex = config_skip.get('branch')
-            if branch_regex:
-                nested_matchers.append(cm.BranchMatcher(branch_regex))
-
-            file_regexes = toList(config_skip.get('all-files-match-any'))
-            if file_regexes:
-                file_matchers = [cm.FileMatcher(x) for x in file_regexes]
-                all_files_matcher = cm.MatchAllFiles(file_matchers)
-                nested_matchers.append(all_files_matcher)
-
-            # All patterns need to match a given skip-if predicate
-            skip_matchers.append(cm.MatchAll(nested_matchers))
-
-        if skip_matchers:
-            # Any skip-if predicate can be matched to trigger a skip
-            return cm.MatchAny(skip_matchers)
-
     def registerConnections(self, connections):
         self.connections = connections
-        for connection_name, connection in self.connections.items():
-            connection.registerScheduler(self)
-            connection.onLoad()
+        self.connections.registerScheduler(self)
 
     def stopConnections(self):
-        for connection_name, connection in self.connections.items():
-            connection.onStop()
-
-    def _getDriver(self, dtype, connection_name, driver_config={}):
-        # Instantiate a driver such as a trigger, source or reporter
-        # TODO(jhesketh): Make this list dynamic or use entrypoints etc.
-        # Stevedore was not a good fit here due to the nature of triggers.
-        # Specifically we don't want to load a trigger per a pipeline as one
-        # trigger can listen to a stream (from gerrit, for example) and the
-        # scheduler decides which eventfilter to use. As such we want to load
-        # trigger+connection pairs uniquely.
-        drivers = {
-            'source': {
-                'gerrit': 'zuul.source.gerrit:GerritSource',
-            },
-            'trigger': {
-                'gerrit': 'zuul.trigger.gerrit:GerritTrigger',
-                'timer': 'zuul.trigger.timer:TimerTrigger',
-                'zuul': 'zuul.trigger.zuultrigger:ZuulTrigger',
-            },
-            'reporter': {
-                'gerrit': 'zuul.reporter.gerrit:GerritReporter',
-                'smtp': 'zuul.reporter.smtp:SMTPReporter',
-            },
-        }
-
-        # TODO(jhesketh): Check the connection_name exists
-        if connection_name in self.connections.keys():
-            driver_name = self.connections[connection_name].driver_name
-            connection = self.connections[connection_name]
-        else:
-            # In some cases a driver may not be related to a connection. For
-            # example, the 'timer' or 'zuul' triggers.
-            driver_name = connection_name
-            connection = None
-        driver = drivers[dtype][driver_name].split(':')
-        driver_instance = getattr(
-            __import__(driver[0], fromlist=['']), driver[1])(
-                driver_config, self, connection
-        )
-
-        return driver_instance
-
-    def _getSourceDriver(self, connection_name):
-        return self._getDriver('source', connection_name)
-
-    def _getReporterDriver(self, connection_name, driver_config={}):
-        return self._getDriver('reporter', connection_name, driver_config)
-
-    def _getTriggerDriver(self, connection_name, driver_config={}):
-        return self._getDriver('trigger', connection_name, driver_config)
-
-    def _parseAbide(self, config_path, connections):
-        abide = model.Abide()
-
-        if config_path:
-            config_path = os.path.expanduser(config_path)
-            if not os.path.exists(config_path):
-                raise Exception("Unable to read tenant config file at %s" %
-                                config_path)
-        with open(config_path) as config_file:
-            self.log.info("Loading configuration from %s" % (config_path,))
-            data = yaml.load(config_file)
-        base = os.path.dirname(os.path.realpath(config_path))
-
-        validator = layoutvalidator.ConfigValidator()
-        validator.validate(data, connections)
-
-        for conf_tenant in data['tenants']:
-            tenant = model.Tenant(conf_tenant['name'])
-            abide.tenants[tenant.name] = tenant
-            tenant_config = {}
-            for fn in conf_tenant.get('include', []):
-                if not os.path.isabs(fn):
-                    fn = os.path.join(base, fn)
-                fn = os.path.expanduser(fn)
-                with open(fn) as config_file:
-                    self.log.info("Loading configuration from %s" % (fn,))
-                    incdata = yaml.load(config_file)
-                    extend_dict(tenant_config, incdata)
-            incdata = self._parseTenantInRepoLayouts(conf_tenant)
-            extend_dict(tenant_config, incdata)
-            tenant.layout = self._parseLayout(base, tenant_config, connections)
-        return abide
-
-    def _parseLayout(self, base, data, connections):
-        layout = model.Layout()
-        project_templates = {}
-
-        validator = layoutvalidator.LayoutValidator()
-        validator.validate(data, connections)
-
-        config_env = {}
-        for include in data.get('includes', []):
-            if 'python-file' in include:
-                fn = include['python-file']
-                if not os.path.isabs(fn):
-                    fn = os.path.join(base, fn)
-                fn = os.path.expanduser(fn)
-                execfile(fn, config_env)
-
-        for conf_pipeline in data.get('pipelines', []):
-            pipeline = Pipeline(conf_pipeline['name'])
-            pipeline.description = conf_pipeline.get('description')
-
-            source_name = conf_pipeline['source']
-            if source_name not in self.sources:
-                self.sources[source_name] = self._getSourceDriver(source_name)
-            pipeline.source = self.sources.get(source_name)
-
-            precedence = model.PRECEDENCE_MAP[conf_pipeline.get('precedence')]
-            pipeline.precedence = precedence
-            pipeline.failure_message = conf_pipeline.get('failure-message',
-                                                         "Build failed.")
-            pipeline.merge_failure_message = conf_pipeline.get(
-                'merge-failure-message', "Merge Failed.\n\nThis change or one "
-                "of its cross-repo dependencies was unable to be "
-                "automatically merged with the current state of its "
-                "repository. Please rebase the change and upload a new "
-                "patchset.")
-            pipeline.success_message = conf_pipeline.get('success-message',
-                                                         "Build succeeded.")
-            pipeline.footer_message = conf_pipeline.get('footer-message', "")
-            pipeline.dequeue_on_new_patchset = conf_pipeline.get(
-                'dequeue-on-new-patchset', True)
-            pipeline.ignore_dependencies = conf_pipeline.get(
-                'ignore-dependencies', False)
-
-            for conf_key, action in self._reporter_actions.items():
-                reporter_set = []
-                if conf_pipeline.get(conf_key):
-                    for reporter_name, params \
-                        in conf_pipeline.get(conf_key).items():
-                        reporter = self._getReporterDriver(reporter_name,
-                                                           params)
-                        reporter.setAction(conf_key)
-                        reporter_set.append(reporter)
-                setattr(pipeline, action, reporter_set)
-
-            # If merge-failure actions aren't explicit, use the failure actions
-            if not pipeline.merge_failure_actions:
-                pipeline.merge_failure_actions = pipeline.failure_actions
-
-            pipeline.disable_at = conf_pipeline.get(
-                'disable-after-consecutive-failures', None)
-
-            pipeline.window = conf_pipeline.get('window', 20)
-            pipeline.window_floor = conf_pipeline.get('window-floor', 3)
-            pipeline.window_increase_type = conf_pipeline.get(
-                'window-increase-type', 'linear')
-            pipeline.window_increase_factor = conf_pipeline.get(
-                'window-increase-factor', 1)
-            pipeline.window_decrease_type = conf_pipeline.get(
-                'window-decrease-type', 'exponential')
-            pipeline.window_decrease_factor = conf_pipeline.get(
-                'window-decrease-factor', 2)
-
-            manager = globals()[conf_pipeline['manager']](self, pipeline)
-            pipeline.setManager(manager)
-            layout.pipelines[conf_pipeline['name']] = pipeline
-
-            if 'require' in conf_pipeline or 'reject' in conf_pipeline:
-                require = conf_pipeline.get('require', {})
-                reject = conf_pipeline.get('reject', {})
-                f = ChangeishFilter(
-                    open=require.get('open'),
-                    current_patchset=require.get('current-patchset'),
-                    statuses=toList(require.get('status')),
-                    required_approvals=toList(require.get('approval')),
-                    reject_approvals=toList(reject.get('approval'))
-                )
-                manager.changeish_filters.append(f)
-
-            for trigger_name, trigger_config\
-                in conf_pipeline.get('trigger').items():
-                if trigger_name not in self.triggers.keys():
-                    self.triggers[trigger_name] = \
-                        self._getTriggerDriver(trigger_name, trigger_config)
-
-            for trigger_name, trigger in self.triggers.items():
-                if trigger_name in conf_pipeline['trigger']:
-                    manager.event_filters += trigger.getEventFilters(
-                        conf_pipeline['trigger'][trigger_name])
-
-        for project_template in data.get('project-templates', []):
-            # Make sure the template only contains valid pipelines
-            tpl = dict(
-                (pipe_name, project_template.get(pipe_name))
-                for pipe_name in layout.pipelines.keys()
-                if pipe_name in project_template
-            )
-            project_templates[project_template.get('name')] = tpl
-
-        for config_job in data.get('jobs', []):
-            job = layout.getJob(config_job['name'])
-            # Be careful to only set attributes explicitly present on
-            # this job, to avoid squashing attributes set by a meta-job.
-            m = config_job.get('queue-name', None)
-            if m:
-                job.queue_name = m
-            m = config_job.get('failure-message', None)
-            if m:
-                job.failure_message = m
-            m = config_job.get('success-message', None)
-            if m:
-                job.success_message = m
-            m = config_job.get('failure-pattern', None)
-            if m:
-                job.failure_pattern = m
-            m = config_job.get('success-pattern', None)
-            if m:
-                job.success_pattern = m
-            m = config_job.get('hold-following-changes', False)
-            if m:
-                job.hold_following_changes = True
-            m = config_job.get('voting', None)
-            if m is not None:
-                job.voting = m
-            fname = config_job.get('parameter-function', None)
-            if fname:
-                func = config_env.get(fname, None)
-                if not func:
-                    raise Exception("Unable to find function %s" % fname)
-                job.parameter_function = func
-            branches = toList(config_job.get('branch'))
-            if branches:
-                job._branches = branches
-                job.branches = [re.compile(x) for x in branches]
-            files = toList(config_job.get('files'))
-            if files:
-                job._files = files
-                job.files = [re.compile(x) for x in files]
-            skip_if_matcher = self._parseSkipIf(config_job)
-            if skip_if_matcher:
-                job.skip_if_matcher = skip_if_matcher
-            swift = toList(config_job.get('swift'))
-            if swift:
-                for s in swift:
-                    job.swift[s['name']] = s
-
-        def add_jobs(job_tree, config_jobs):
-            for job in config_jobs:
-                if isinstance(job, list):
-                    for x in job:
-                        add_jobs(job_tree, x)
-                if isinstance(job, dict):
-                    for parent, children in job.items():
-                        parent_tree = job_tree.addJob(layout.getJob(parent))
-                        add_jobs(parent_tree, children)
-                if isinstance(job, str):
-                    job_tree.addJob(layout.getJob(job))
-
-        for config_project in data.get('projects', []):
-            shortname = config_project['name'].split('/')[-1]
-
-            # This is reversed due to the prepend operation below, so
-            # the ultimate order is templates (in order) followed by
-            # statically defined jobs.
-            for requested_template in reversed(
-                config_project.get('template', [])):
-                # Fetch the template from 'project-templates'
-                tpl = project_templates.get(
-                    requested_template.get('name'))
-                # Expand it with the project context
-                requested_template['name'] = shortname
-                expanded = deep_format(tpl, requested_template)
-                # Finally merge the expansion with whatever has been
-                # already defined for this project.  Prepend our new
-                # jobs to existing ones (which may have been
-                # statically defined or defined by other templates).
-                for pipeline in layout.pipelines.values():
-                    if pipeline.name in expanded:
-                        config_project.update(
-                            {pipeline.name: expanded[pipeline.name] +
-                             config_project.get(pipeline.name, [])})
-
-            mode = config_project.get('merge-mode', 'merge-resolve')
-            for pipeline in layout.pipelines.values():
-                if pipeline.name in config_project:
-                    project = pipeline.source.getProject(
-                        config_project['name'])
-                    project.merge_mode = model.MERGER_MAP[mode]
-                    job_tree = pipeline.addProject(project)
-                    config_jobs = config_project[pipeline.name]
-                    add_jobs(job_tree, config_jobs)
-
-        for pipeline in layout.pipelines.values():
-            pipeline.manager._postConfig(layout)
-
-        return layout
-
-    def _parseTenantInRepoLayouts(self, conf_tenant):
-        config = {}
-        jobs = []
-        for source_name, conf_source in conf_tenant.get('source', {}).items():
-            # TODOv3(jeblair,jhesketh): sources should just be
-            # set up at the start of the zuul.conf parsing
-            if source_name not in self.sources:
-                self.sources[source_name] = self._getSourceDriver(
-                    source_name)
-            for conf_repo in conf_source.get('repos'):
-                source = self.sources[source_name]
-                project = source.getProject(conf_repo)
-                url = source.getGitUrl(project)
-                # TODOv3(jeblair): config should be branch specific
-                job = self.merger.getFiles(project.name, url, 'master',
-                                           files=['.zuul.yaml'])
-                job.project = project
-                jobs.append(job)
-        for job in jobs:
-            self.log.debug("Waiting for cat job %s" % (job,))
-            job.wait()
-            if job.files.get('.zuul.yaml'):
-                self.log.info("Loading configuration from %s/.zuul.yaml" %
-                              (job.project,))
-                incdata = self._parseInRepoLayout(job.files['.zuul.yaml'])
-                extend_dict(config, incdata)
-        return config
-
-    def _parseInRepoLayout(self, data):
-        # TODOv3(jeblair): this should implement some rules to protect
-        # aspects of the config that should not be changed in-repo
-        return yaml.load(data)
+        self.connections.stop()
 
     def setLauncher(self, launcher):
         self.launcher = launcher
@@ -617,6 +207,7 @@
         try:
             p = self.layout.projects.get(name)
             if p is None and create_foreign:
+                # TODOv3(jeblair): fix
                 self.log.info("Registering foreign project: %s" % name)
                 p = Project(name, foreign=True)
                 self.layout.projects[name] = p
@@ -786,8 +377,10 @@
         self.config = event.config
         try:
             self.log.debug("Performing reconfiguration")
-            abide = self._parseAbide(
-                self.config.get('zuul', 'tenant_config'), self.connections)
+            loader = configloader.ConfigLoader()
+            abide = loader.loadConfig(
+                self.config.get('zuul', 'tenant_config'),
+                self, self.merger, self.connections)
             for tenant in abide.tenants.values():
                 self._reconfigureTenant(tenant)
             self.abide = abide
@@ -846,13 +439,11 @@
                         "for change %s" % (build, item.change))
         # TODOv3(jeblair): update for tenants
         self.maintainTriggerCache()
-        for trigger in self.triggers.values():
-            trigger.postConfig()
         for pipeline in tenant.layout.pipelines.values():
             pipeline.source.postConfig()
-            for action in self._reporter_actions.values():
-                for reporter in pipeline.__getattribute__(action):
-                    reporter.postConfig()
+            pipeline.trigger.postConfig()
+            for reporter in pipeline.actions:
+                reporter.postConfig()
         if statsd:
             try:
                 for pipeline in self.layout.pipelines.values():
@@ -1119,1016 +710,3 @@
         for pipeline in self.layout.pipelines.values():
             pipelines.append(pipeline.formatStatusJSON())
         return json.dumps(data)
-
-
-class BasePipelineManager(object):
-    log = logging.getLogger("zuul.BasePipelineManager")
-
-    def __init__(self, sched, pipeline):
-        self.sched = sched
-        self.pipeline = pipeline
-        self.event_filters = []
-        self.changeish_filters = []
-
-    def __str__(self):
-        return "<%s %s>" % (self.__class__.__name__, self.pipeline.name)
-
-    def _postConfig(self, layout):
-        self.log.info("Configured Pipeline Manager %s" % self.pipeline.name)
-        self.log.info("  Source: %s" % self.pipeline.source)
-        self.log.info("  Requirements:")
-        for f in self.changeish_filters:
-            self.log.info("    %s" % f)
-        self.log.info("  Events:")
-        for e in self.event_filters:
-            self.log.info("    %s" % e)
-        self.log.info("  Projects:")
-
-        def log_jobs(tree, indent=0):
-            istr = '    ' + ' ' * indent
-            if tree.job:
-                efilters = ''
-                for b in tree.job._branches:
-                    efilters += str(b)
-                for f in tree.job._files:
-                    efilters += str(f)
-                if tree.job.skip_if_matcher:
-                    efilters += str(tree.job.skip_if_matcher)
-                if efilters:
-                    efilters = ' ' + efilters
-                hold = ''
-                if tree.job.hold_following_changes:
-                    hold = ' [hold]'
-                voting = ''
-                if not tree.job.voting:
-                    voting = ' [nonvoting]'
-                self.log.info("%s%s%s%s%s" % (istr, repr(tree.job),
-                                              efilters, hold, voting))
-            for x in tree.job_trees:
-                log_jobs(x, indent + 2)
-
-        for p in layout.projects.values():
-            tree = self.pipeline.getJobTree(p)
-            if tree:
-                self.log.info("    %s" % p)
-                log_jobs(tree)
-        self.log.info("  On start:")
-        self.log.info("    %s" % self.pipeline.start_actions)
-        self.log.info("  On success:")
-        self.log.info("    %s" % self.pipeline.success_actions)
-        self.log.info("  On failure:")
-        self.log.info("    %s" % self.pipeline.failure_actions)
-        self.log.info("  On merge-failure:")
-        self.log.info("    %s" % self.pipeline.merge_failure_actions)
-        self.log.info("  When disabled:")
-        self.log.info("    %s" % self.pipeline.disabled_actions)
-
-    def getSubmitAllowNeeds(self):
-        # Get a list of code review labels that are allowed to be
-        # "needed" in the submit records for a change, with respect
-        # to this queue.  In other words, the list of review labels
-        # this queue itself is likely to set before submitting.
-        allow_needs = set()
-        for action_reporter in self.pipeline.success_actions:
-            allow_needs.update(action_reporter.getSubmitAllowNeeds())
-        return allow_needs
-
-    def eventMatches(self, event, change):
-        if event.forced_pipeline:
-            if event.forced_pipeline == self.pipeline.name:
-                self.log.debug("Event %s for change %s was directly assigned "
-                               "to pipeline %s" % (event, change, self))
-                return True
-            else:
-                return False
-        for ef in self.event_filters:
-            if ef.matches(event, change):
-                self.log.debug("Event %s for change %s matched %s "
-                               "in pipeline %s" % (event, change, ef, self))
-                return True
-        return False
-
-    def isChangeAlreadyInPipeline(self, change):
-        # Checks live items in the pipeline
-        for item in self.pipeline.getAllItems():
-            if item.live and change.equals(item.change):
-                return True
-        return False
-
-    def isChangeAlreadyInQueue(self, change, change_queue):
-        # Checks any item in the specified change queue
-        for item in change_queue.queue:
-            if change.equals(item.change):
-                return True
-        return False
-
-    def reportStart(self, item):
-        if not self.pipeline._disabled:
-            try:
-                self.log.info("Reporting start, action %s item %s" %
-                              (self.pipeline.start_actions, item))
-                ret = self.sendReport(self.pipeline.start_actions,
-                                      self.pipeline.source, item)
-                if ret:
-                    self.log.error("Reporting item start %s received: %s" %
-                                   (item, ret))
-            except:
-                self.log.exception("Exception while reporting start:")
-
-    def sendReport(self, action_reporters, source, item,
-                   message=None):
-        """Sends the built message off to configured reporters.
-
-        Takes the action_reporters, item, message and extra options and
-        sends them to the pluggable reporters.
-        """
-        report_errors = []
-        if len(action_reporters) > 0:
-            for reporter in action_reporters:
-                ret = reporter.report(source, self.pipeline, item)
-                if ret:
-                    report_errors.append(ret)
-            if len(report_errors) == 0:
-                return
-        return report_errors
-
-    def isChangeReadyToBeEnqueued(self, change):
-        return True
-
-    def enqueueChangesAhead(self, change, quiet, ignore_requirements,
-                            change_queue):
-        return True
-
-    def enqueueChangesBehind(self, change, quiet, ignore_requirements,
-                             change_queue):
-        return True
-
-    def checkForChangesNeededBy(self, change, change_queue):
-        return True
-
-    def getFailingDependentItems(self, item):
-        return None
-
-    def getDependentItems(self, item):
-        orig_item = item
-        items = []
-        while item.item_ahead:
-            items.append(item.item_ahead)
-            item = item.item_ahead
-        self.log.info("Change %s depends on changes %s" %
-                      (orig_item.change,
-                       [x.change for x in items]))
-        return items
-
-    def getItemForChange(self, change):
-        for item in self.pipeline.getAllItems():
-            if item.change.equals(change):
-                return item
-        return None
-
-    def findOldVersionOfChangeAlreadyInQueue(self, change):
-        for item in self.pipeline.getAllItems():
-            if not item.live:
-                continue
-            if change.isUpdateOf(item.change):
-                return item
-        return None
-
-    def removeOldVersionsOfChange(self, change):
-        if not self.pipeline.dequeue_on_new_patchset:
-            return
-        old_item = self.findOldVersionOfChangeAlreadyInQueue(change)
-        if old_item:
-            self.log.debug("Change %s is a new version of %s, removing %s" %
-                           (change, old_item.change, old_item))
-            self.removeItem(old_item)
-
-    def removeAbandonedChange(self, change):
-        self.log.debug("Change %s abandoned, removing." % change)
-        for item in self.pipeline.getAllItems():
-            if not item.live:
-                continue
-            if item.change.equals(change):
-                self.removeItem(item)
-
-    def reEnqueueItem(self, item, last_head):
-        with self.getChangeQueue(item.change, last_head.queue) as change_queue:
-            if change_queue:
-                self.log.debug("Re-enqueing change %s in queue %s" %
-                               (item.change, change_queue))
-                change_queue.enqueueItem(item)
-
-                # Re-set build results in case any new jobs have been
-                # added to the tree.
-                for build in item.current_build_set.getBuilds():
-                    if build.result:
-                        self.pipeline.setResult(item, build)
-                # Similarly, reset the item state.
-                if item.current_build_set.unable_to_merge:
-                    self.pipeline.setUnableToMerge(item)
-                if item.dequeued_needing_change:
-                    self.pipeline.setDequeuedNeedingChange(item)
-
-                self.reportStats(item)
-                return True
-            else:
-                self.log.error("Unable to find change queue for project %s" %
-                               item.change.project)
-                return False
-
-    def addChange(self, change, quiet=False, enqueue_time=None,
-                  ignore_requirements=False, live=True,
-                  change_queue=None):
-        self.log.debug("Considering adding change %s" % change)
-
-        # If we are adding a live change, check if it's a live item
-        # anywhere in the pipeline.  Otherwise, we will perform the
-        # duplicate check below on the specific change_queue.
-        if live and self.isChangeAlreadyInPipeline(change):
-            self.log.debug("Change %s is already in pipeline, "
-                           "ignoring" % change)
-            return True
-
-        if not self.isChangeReadyToBeEnqueued(change):
-            self.log.debug("Change %s is not ready to be enqueued, ignoring" %
-                           change)
-            return False
-
-        if not ignore_requirements:
-            for f in self.changeish_filters:
-                if not f.matches(change):
-                    self.log.debug("Change %s does not match pipeline "
-                                   "requirement %s" % (change, f))
-                    return False
-
-        with self.getChangeQueue(change, change_queue) as change_queue:
-            if not change_queue:
-                self.log.debug("Unable to find change queue for "
-                               "change %s in project %s" %
-                               (change, change.project))
-                return False
-
-            if not self.enqueueChangesAhead(change, quiet, ignore_requirements,
-                                            change_queue):
-                self.log.debug("Failed to enqueue changes "
-                               "ahead of %s" % change)
-                return False
-
-            if self.isChangeAlreadyInQueue(change, change_queue):
-                self.log.debug("Change %s is already in queue, "
-                               "ignoring" % change)
-                return True
-
-            self.log.debug("Adding change %s to queue %s" %
-                           (change, change_queue))
-            item = change_queue.enqueueChange(change)
-            if enqueue_time:
-                item.enqueue_time = enqueue_time
-            item.live = live
-            self.reportStats(item)
-            if not quiet:
-                if len(self.pipeline.start_actions) > 0:
-                    self.reportStart(item)
-            self.enqueueChangesBehind(change, quiet, ignore_requirements,
-                                      change_queue)
-            for trigger in self.sched.triggers.values():
-                trigger.onChangeEnqueued(item.change, self.pipeline)
-            return True
-
-    def dequeueItem(self, item):
-        self.log.debug("Removing change %s from queue" % item.change)
-        item.queue.dequeueItem(item)
-
-    def removeItem(self, item):
-        # Remove an item from the queue, probably because it has been
-        # superseded by another change.
-        self.log.debug("Canceling builds behind change: %s "
-                       "because it is being removed." % item.change)
-        self.cancelJobs(item)
-        self.dequeueItem(item)
-        self.reportStats(item)
-
-    def _makeMergerItem(self, item):
-        # Create a dictionary with all info about the item needed by
-        # the merger.
-        number = None
-        patchset = None
-        oldrev = None
-        newrev = None
-        if hasattr(item.change, 'number'):
-            number = item.change.number
-            patchset = item.change.patchset
-        elif hasattr(item.change, 'newrev'):
-            oldrev = item.change.oldrev
-            newrev = item.change.newrev
-        connection_name = self.pipeline.source.connection.connection_name
-        return dict(project=item.change.project.name,
-                    url=self.pipeline.source.getGitUrl(
-                        item.change.project),
-                    connection_name=connection_name,
-                    merge_mode=item.change.project.merge_mode,
-                    refspec=item.change.refspec,
-                    branch=item.change.branch,
-                    ref=item.current_build_set.ref,
-                    number=number,
-                    patchset=patchset,
-                    oldrev=oldrev,
-                    newrev=newrev,
-                    )
-
-    def prepareRef(self, item):
-        # Returns True if the ref is ready, false otherwise
-        build_set = item.current_build_set
-        if build_set.merge_state == build_set.COMPLETE:
-            return True
-        if build_set.merge_state == build_set.PENDING:
-            return False
-        build_set.merge_state = build_set.PENDING
-        ref = build_set.ref
-        if hasattr(item.change, 'refspec') and not ref:
-            self.log.debug("Preparing ref for: %s" % item.change)
-            item.current_build_set.setConfiguration()
-            dependent_items = self.getDependentItems(item)
-            dependent_items.reverse()
-            all_items = dependent_items + [item]
-            merger_items = map(self._makeMergerItem, all_items)
-            self.sched.merger.mergeChanges(merger_items,
-                                           item.current_build_set,
-                                           self.pipeline.precedence)
-        else:
-            self.log.debug("Preparing update repo for: %s" % item.change)
-            url = self.pipeline.source.getGitUrl(item.change.project)
-            self.sched.merger.updateRepo(item.change.project.name,
-                                         url, build_set,
-                                         self.pipeline.precedence)
-        return False
-
-    def _launchJobs(self, item, jobs):
-        self.log.debug("Launching jobs for change %s" % item.change)
-        dependent_items = self.getDependentItems(item)
-        for job in jobs:
-            self.log.debug("Found job %s for change %s" % (job, item.change))
-            try:
-                build = self.sched.launcher.launch(job, item,
-                                                   self.pipeline,
-                                                   dependent_items)
-                self.log.debug("Adding build %s of job %s to item %s" %
-                               (build, job, item))
-                item.addBuild(build)
-            except:
-                self.log.exception("Exception while launching job %s "
-                                   "for change %s:" % (job, item.change))
-
-    def launchJobs(self, item):
-        jobs = self.pipeline.findJobsToRun(item)
-        if jobs:
-            self._launchJobs(item, jobs)
-
-    def cancelJobs(self, item, prime=True):
-        self.log.debug("Cancel jobs for change %s" % item.change)
-        canceled = False
-        old_build_set = item.current_build_set
-        if prime and item.current_build_set.ref:
-            item.resetAllBuilds()
-        for build in old_build_set.getBuilds():
-            try:
-                self.sched.launcher.cancel(build)
-            except:
-                self.log.exception("Exception while canceling build %s "
-                                   "for change %s" % (build, item.change))
-            build.result = 'CANCELED'
-            canceled = True
-        self.updateBuildDescriptions(old_build_set)
-        for item_behind in item.items_behind:
-            self.log.debug("Canceling jobs for change %s, behind change %s" %
-                           (item_behind.change, item.change))
-            if self.cancelJobs(item_behind, prime=prime):
-                canceled = True
-        return canceled
-
-    def _processOneItem(self, item, nnfi):
-        changed = False
-        item_ahead = item.item_ahead
-        if item_ahead and (not item_ahead.live):
-            item_ahead = None
-        change_queue = item.queue
-        failing_reasons = []  # Reasons this item is failing
-
-        if self.checkForChangesNeededBy(item.change, change_queue) is not True:
-            # It's not okay to enqueue this change, we should remove it.
-            self.log.info("Dequeuing change %s because "
-                          "it can no longer merge" % item.change)
-            self.cancelJobs(item)
-            self.dequeueItem(item)
-            self.pipeline.setDequeuedNeedingChange(item)
-            if item.live:
-                try:
-                    self.reportItem(item)
-                except exceptions.MergeFailure:
-                    pass
-            return (True, nnfi)
-        dep_items = self.getFailingDependentItems(item)
-        actionable = change_queue.isActionable(item)
-        item.active = actionable
-        ready = False
-        if dep_items:
-            failing_reasons.append('a needed change is failing')
-            self.cancelJobs(item, prime=False)
-        else:
-            item_ahead_merged = False
-            if (item_ahead and item_ahead.change.is_merged):
-                item_ahead_merged = True
-            if (item_ahead != nnfi and not item_ahead_merged):
-                # Our current base is different than what we expected,
-                # and it's not because our current base merged.  Something
-                # ahead must have failed.
-                self.log.info("Resetting builds for change %s because the "
-                              "item ahead, %s, is not the nearest non-failing "
-                              "item, %s" % (item.change, item_ahead, nnfi))
-                change_queue.moveItem(item, nnfi)
-                changed = True
-                self.cancelJobs(item)
-            if actionable:
-                ready = self.prepareRef(item)
-                if item.current_build_set.unable_to_merge:
-                    failing_reasons.append("it has a merge conflict")
-                    ready = False
-        if actionable and ready and self.launchJobs(item):
-            changed = True
-        if self.pipeline.didAnyJobFail(item):
-            failing_reasons.append("at least one job failed")
-        if (not item.live) and (not item.items_behind):
-            failing_reasons.append("is a non-live item with no items behind")
-            self.dequeueItem(item)
-            changed = True
-        if ((not item_ahead) and self.pipeline.areAllJobsComplete(item)
-            and item.live):
-            try:
-                self.reportItem(item)
-            except exceptions.MergeFailure:
-                failing_reasons.append("it did not merge")
-                for item_behind in item.items_behind:
-                    self.log.info("Resetting builds for change %s because the "
-                                  "item ahead, %s, failed to merge" %
-                                  (item_behind.change, item))
-                    self.cancelJobs(item_behind)
-            self.dequeueItem(item)
-            changed = True
-        elif not failing_reasons and item.live:
-            nnfi = item
-        item.current_build_set.failing_reasons = failing_reasons
-        if failing_reasons:
-            self.log.debug("%s is a failing item because %s" %
-                           (item, failing_reasons))
-        return (changed, nnfi)
-
-    def processQueue(self):
-        # Do whatever needs to be done for each change in the queue
-        self.log.debug("Starting queue processor: %s" % self.pipeline.name)
-        changed = False
-        for queue in self.pipeline.queues:
-            queue_changed = False
-            nnfi = None  # Nearest non-failing item
-            for item in queue.queue[:]:
-                item_changed, nnfi = self._processOneItem(
-                    item, nnfi)
-                if item_changed:
-                    queue_changed = True
-                self.reportStats(item)
-            if queue_changed:
-                changed = True
-                status = ''
-                for item in queue.queue:
-                    status += item.formatStatus()
-                if status:
-                    self.log.debug("Queue %s status is now:\n %s" %
-                                   (queue.name, status))
-        self.log.debug("Finished queue processor: %s (changed: %s)" %
-                       (self.pipeline.name, changed))
-        return changed
-
-    def updateBuildDescriptions(self, build_set):
-        for build in build_set.getBuilds():
-            desc = self.formatDescription(build)
-            self.sched.launcher.setBuildDescription(build, desc)
-
-        if build_set.previous_build_set:
-            for build in build_set.previous_build_set.getBuilds():
-                desc = self.formatDescription(build)
-                self.sched.launcher.setBuildDescription(build, desc)
-
-    def onBuildStarted(self, build):
-        self.log.debug("Build %s started" % build)
-        return True
-
-    def onBuildCompleted(self, build):
-        self.log.debug("Build %s completed" % build)
-        item = build.build_set.item
-
-        self.pipeline.setResult(item, build)
-        self.log.debug("Item %s status is now:\n %s" %
-                       (item, item.formatStatus()))
-        return True
-
-    def onMergeCompleted(self, event):
-        build_set = event.build_set
-        item = build_set.item
-        build_set.merge_state = build_set.COMPLETE
-        build_set.zuul_url = event.zuul_url
-        if event.merged:
-            build_set.commit = event.commit
-        elif event.updated:
-            if not isinstance(item, NullChange):
-                build_set.commit = item.change.newrev
-        if not build_set.commit:
-            self.log.info("Unable to merge change %s" % item.change)
-            self.pipeline.setUnableToMerge(item)
-
-    def reportItem(self, item):
-        if not item.reported:
-            # _reportItem() returns True if it failed to report.
-            item.reported = not self._reportItem(item)
-        if self.changes_merge:
-            succeeded = self.pipeline.didAllJobsSucceed(item)
-            merged = item.reported
-            if merged:
-                merged = self.pipeline.source.isMerged(item.change,
-                                                       item.change.branch)
-            self.log.info("Reported change %s status: all-succeeded: %s, "
-                          "merged: %s" % (item.change, succeeded, merged))
-            change_queue = item.queue
-            if not (succeeded and merged):
-                self.log.debug("Reported change %s failed tests or failed "
-                               "to merge" % (item.change))
-                change_queue.decreaseWindowSize()
-                self.log.debug("%s window size decreased to %s" %
-                               (change_queue, change_queue.window))
-                raise exceptions.MergeFailure(
-                    "Change %s failed to merge" % item.change)
-            else:
-                change_queue.increaseWindowSize()
-                self.log.debug("%s window size increased to %s" %
-                               (change_queue, change_queue.window))
-
-                for trigger in self.sched.triggers.values():
-                    trigger.onChangeMerged(item.change, self.pipeline.source)
-
-    def _reportItem(self, item):
-        self.log.debug("Reporting change %s" % item.change)
-        ret = True  # Means error as returned by trigger.report
-        if not self.pipeline.getJobs(item):
-            # We don't send empty reports with +1,
-            # and the same for -1's (merge failures or transient errors)
-            # as they cannot be followed by +1's
-            self.log.debug("No jobs for change %s" % item.change)
-            actions = []
-        elif self.pipeline.didAllJobsSucceed(item):
-            self.log.debug("success %s" % (self.pipeline.success_actions))
-            actions = self.pipeline.success_actions
-            item.setReportedResult('SUCCESS')
-            self.pipeline._consecutive_failures = 0
-        elif not self.pipeline.didMergerSucceed(item):
-            actions = self.pipeline.merge_failure_actions
-            item.setReportedResult('MERGER_FAILURE')
-        else:
-            actions = self.pipeline.failure_actions
-            item.setReportedResult('FAILURE')
-            self.pipeline._consecutive_failures += 1
-        if self.pipeline._disabled:
-            actions = self.pipeline.disabled_actions
-        # Check here if we should disable so that we only use the disabled
-        # reporters /after/ the last disable_at failure is still reported as
-        # normal.
-        if (self.pipeline.disable_at and not self.pipeline._disabled and
-            self.pipeline._consecutive_failures >= self.pipeline.disable_at):
-            self.pipeline._disabled = True
-        if actions:
-            try:
-                self.log.info("Reporting item %s, actions: %s" %
-                              (item, actions))
-                ret = self.sendReport(actions, self.pipeline.source, item)
-                if ret:
-                    self.log.error("Reporting item %s received: %s" %
-                                   (item, ret))
-            except:
-                self.log.exception("Exception while reporting:")
-                item.setReportedResult('ERROR')
-        self.updateBuildDescriptions(item.current_build_set)
-        return ret
-
-    def formatDescription(self, build):
-        concurrent_changes = ''
-        concurrent_builds = ''
-        other_builds = ''
-
-        for change in build.build_set.other_changes:
-            concurrent_changes += '<li><a href="{change.url}">\
-              {change.number},{change.patchset}</a></li>'.format(
-                change=change)
-
-        change = build.build_set.item.change
-
-        for build in build.build_set.getBuilds():
-            if build.url:
-                concurrent_builds += """\
-<li>
-  <a href="{build.url}">
-  {build.job.name} #{build.number}</a>: {build.result}
-</li>
-""".format(build=build)
-            else:
-                concurrent_builds += """\
-<li>
-  {build.job.name}: {build.result}
-</li>""".format(build=build)
-
-        if build.build_set.previous_build_set:
-            other_build = build.build_set.previous_build_set.getBuild(
-                build.job.name)
-            if other_build:
-                other_builds += """\
-<li>
-  Preceded by: <a href="{build.url}">
-  {build.job.name} #{build.number}</a>
-</li>
-""".format(build=other_build)
-
-        if build.build_set.next_build_set:
-            other_build = build.build_set.next_build_set.getBuild(
-                build.job.name)
-            if other_build:
-                other_builds += """\
-<li>
-  Succeeded by: <a href="{build.url}">
-  {build.job.name} #{build.number}</a>
-</li>
-""".format(build=other_build)
-
-        result = build.build_set.result
-
-        if hasattr(change, 'number'):
-            ret = """\
-<p>
-  Triggered by change:
-    <a href="{change.url}">{change.number},{change.patchset}</a><br/>
-  Branch: <b>{change.branch}</b><br/>
-  Pipeline: <b>{self.pipeline.name}</b>
-</p>"""
-        elif hasattr(change, 'ref'):
-            ret = """\
-<p>
-  Triggered by reference:
-    {change.ref}</a><br/>
-  Old revision: <b>{change.oldrev}</b><br/>
-  New revision: <b>{change.newrev}</b><br/>
-  Pipeline: <b>{self.pipeline.name}</b>
-</p>"""
-        else:
-            ret = ""
-
-        if concurrent_changes:
-            ret += """\
-<p>
-  Other changes tested concurrently with this change:
-  <ul>{concurrent_changes}</ul>
-</p>
-"""
-        if concurrent_builds:
-            ret += """\
-<p>
-  All builds for this change set:
-  <ul>{concurrent_builds}</ul>
-</p>
-"""
-
-        if other_builds:
-            ret += """\
-<p>
-  Other build sets for this change:
-  <ul>{other_builds}</ul>
-</p>
-"""
-        if result:
-            ret += """\
-<p>
-  Reported result: <b>{result}</b>
-</p>
-"""
-
-        ret = ret.format(**locals())
-        return ret
-
-    def reportStats(self, item):
-        if not statsd:
-            return
-        try:
-            # Update the gauge on enqueue and dequeue, but timers only
-            # when dequeing.
-            if item.dequeue_time:
-                dt = int((item.dequeue_time - item.enqueue_time) * 1000)
-            else:
-                dt = None
-            items = len(self.pipeline.getAllItems())
-
-            # stats.timers.zuul.pipeline.NAME.resident_time
-            # stats_counts.zuul.pipeline.NAME.total_changes
-            # stats.gauges.zuul.pipeline.NAME.current_changes
-            key = 'zuul.pipeline.%s' % self.pipeline.name
-            statsd.gauge(key + '.current_changes', items)
-            if dt:
-                statsd.timing(key + '.resident_time', dt)
-                statsd.incr(key + '.total_changes')
-
-            # stats.timers.zuul.pipeline.NAME.ORG.PROJECT.resident_time
-            # stats_counts.zuul.pipeline.NAME.ORG.PROJECT.total_changes
-            project_name = item.change.project.name.replace('/', '.')
-            key += '.%s' % project_name
-            if dt:
-                statsd.timing(key + '.resident_time', dt)
-                statsd.incr(key + '.total_changes')
-        except:
-            self.log.exception("Exception reporting pipeline stats")
-
-
-class DynamicChangeQueueContextManager(object):
-    def __init__(self, change_queue):
-        self.change_queue = change_queue
-
-    def __enter__(self):
-        return self.change_queue
-
-    def __exit__(self, etype, value, tb):
-        if self.change_queue and not self.change_queue.queue:
-            self.change_queue.pipeline.removeQueue(self.change_queue.queue)
-
-
-class IndependentPipelineManager(BasePipelineManager):
-    log = logging.getLogger("zuul.IndependentPipelineManager")
-    changes_merge = False
-
-    def _postConfig(self, layout):
-        super(IndependentPipelineManager, self)._postConfig(layout)
-
-    def getChangeQueue(self, change, existing=None):
-        # creates a new change queue for every change
-        if existing:
-            return DynamicChangeQueueContextManager(existing)
-        if change.project not in self.pipeline.getProjects():
-            self.pipeline.addProject(change.project)
-        change_queue = ChangeQueue(self.pipeline)
-        change_queue.addProject(change.project)
-        self.pipeline.addQueue(change_queue)
-        self.log.debug("Dynamically created queue %s", change_queue)
-        return DynamicChangeQueueContextManager(change_queue)
-
-    def enqueueChangesAhead(self, change, quiet, ignore_requirements,
-                            change_queue):
-        ret = self.checkForChangesNeededBy(change, change_queue)
-        if ret in [True, False]:
-            return ret
-        self.log.debug("  Changes %s must be merged ahead of %s" %
-                       (ret, change))
-        for needed_change in ret:
-            # This differs from the dependent pipeline by enqueuing
-            # changes ahead as "not live", that is, not intended to
-            # have jobs run.  Also, pipeline requirements are always
-            # ignored (which is safe because the changes are not
-            # live).
-            r = self.addChange(needed_change, quiet=True,
-                               ignore_requirements=True,
-                               live=False, change_queue=change_queue)
-            if not r:
-                return False
-        return True
-
-    def checkForChangesNeededBy(self, change, change_queue):
-        if self.pipeline.ignore_dependencies:
-            return True
-        self.log.debug("Checking for changes needed by %s:" % change)
-        # Return true if okay to proceed enqueing this change,
-        # false if the change should not be enqueued.
-        if not hasattr(change, 'needs_changes'):
-            self.log.debug("  Changeish does not support dependencies")
-            return True
-        if not change.needs_changes:
-            self.log.debug("  No changes needed")
-            return True
-        changes_needed = []
-        for needed_change in change.needs_changes:
-            self.log.debug("  Change %s needs change %s:" % (
-                change, needed_change))
-            if needed_change.is_merged:
-                self.log.debug("  Needed change is merged")
-                continue
-            if self.isChangeAlreadyInQueue(needed_change, change_queue):
-                self.log.debug("  Needed change is already ahead in the queue")
-                continue
-            self.log.debug("  Change %s is needed" % needed_change)
-            if needed_change not in changes_needed:
-                changes_needed.append(needed_change)
-                continue
-            # This differs from the dependent pipeline check in not
-            # verifying that the dependent change is mergable.
-        if changes_needed:
-            return changes_needed
-        return True
-
-    def dequeueItem(self, item):
-        super(IndependentPipelineManager, self).dequeueItem(item)
-        # An independent pipeline manager dynamically removes empty
-        # queues
-        if not item.queue.queue:
-            self.pipeline.removeQueue(item.queue)
-
-
-class StaticChangeQueueContextManager(object):
-    def __init__(self, change_queue):
-        self.change_queue = change_queue
-
-    def __enter__(self):
-        return self.change_queue
-
-    def __exit__(self, etype, value, tb):
-        pass
-
-
-class DependentPipelineManager(BasePipelineManager):
-    log = logging.getLogger("zuul.DependentPipelineManager")
-    changes_merge = True
-
-    def __init__(self, *args, **kwargs):
-        super(DependentPipelineManager, self).__init__(*args, **kwargs)
-
-    def _postConfig(self, layout):
-        super(DependentPipelineManager, self)._postConfig(layout)
-        self.buildChangeQueues()
-
-    def buildChangeQueues(self):
-        self.log.debug("Building shared change queues")
-        change_queues = []
-
-        for project in self.pipeline.getProjects():
-            change_queue = ChangeQueue(
-                self.pipeline,
-                window=self.pipeline.window,
-                window_floor=self.pipeline.window_floor,
-                window_increase_type=self.pipeline.window_increase_type,
-                window_increase_factor=self.pipeline.window_increase_factor,
-                window_decrease_type=self.pipeline.window_decrease_type,
-                window_decrease_factor=self.pipeline.window_decrease_factor)
-            change_queue.addProject(project)
-            change_queues.append(change_queue)
-            self.log.debug("Created queue: %s" % change_queue)
-
-        # Iterate over all queues trying to combine them, and keep doing
-        # so until they can not be combined further.
-        last_change_queues = change_queues
-        while True:
-            new_change_queues = self.combineChangeQueues(last_change_queues)
-            if len(last_change_queues) == len(new_change_queues):
-                break
-            last_change_queues = new_change_queues
-
-        self.log.info("  Shared change queues:")
-        for queue in new_change_queues:
-            self.pipeline.addQueue(queue)
-            self.log.info("    %s containing %s" % (
-                queue, queue.generated_name))
-
-    def combineChangeQueues(self, change_queues):
-        self.log.debug("Combining shared queues")
-        new_change_queues = []
-        for a in change_queues:
-            merged_a = False
-            for b in new_change_queues:
-                if not a.getJobs().isdisjoint(b.getJobs()):
-                    self.log.debug("Merging queue %s into %s" % (a, b))
-                    b.mergeChangeQueue(a)
-                    merged_a = True
-                    break  # this breaks out of 'for b' and continues 'for a'
-            if not merged_a:
-                self.log.debug("Keeping queue %s" % (a))
-                new_change_queues.append(a)
-        return new_change_queues
-
-    def getChangeQueue(self, change, existing=None):
-        if existing:
-            return StaticChangeQueueContextManager(existing)
-        return StaticChangeQueueContextManager(
-            self.pipeline.getQueue(change.project))
-
-    def isChangeReadyToBeEnqueued(self, change):
-        if not self.pipeline.source.canMerge(change,
-                                             self.getSubmitAllowNeeds()):
-            self.log.debug("Change %s can not merge, ignoring" % change)
-            return False
-        return True
-
-    def enqueueChangesBehind(self, change, quiet, ignore_requirements,
-                             change_queue):
-        to_enqueue = []
-        self.log.debug("Checking for changes needing %s:" % change)
-        if not hasattr(change, 'needed_by_changes'):
-            self.log.debug("  Changeish does not support dependencies")
-            return
-        for other_change in change.needed_by_changes:
-            with self.getChangeQueue(other_change) as other_change_queue:
-                if other_change_queue != change_queue:
-                    self.log.debug("  Change %s in project %s can not be "
-                                   "enqueued in the target queue %s" %
-                                   (other_change, other_change.project,
-                                    change_queue))
-                    continue
-            if self.pipeline.source.canMerge(other_change,
-                                             self.getSubmitAllowNeeds()):
-                self.log.debug("  Change %s needs %s and is ready to merge" %
-                               (other_change, change))
-                to_enqueue.append(other_change)
-
-        if not to_enqueue:
-            self.log.debug("  No changes need %s" % change)
-
-        for other_change in to_enqueue:
-            self.addChange(other_change, quiet=quiet,
-                           ignore_requirements=ignore_requirements,
-                           change_queue=change_queue)
-
-    def enqueueChangesAhead(self, change, quiet, ignore_requirements,
-                            change_queue):
-        ret = self.checkForChangesNeededBy(change, change_queue)
-        if ret in [True, False]:
-            return ret
-        self.log.debug("  Changes %s must be merged ahead of %s" %
-                       (ret, change))
-        for needed_change in ret:
-            r = self.addChange(needed_change, quiet=quiet,
-                               ignore_requirements=ignore_requirements,
-                               change_queue=change_queue)
-            if not r:
-                return False
-        return True
-
-    def checkForChangesNeededBy(self, change, change_queue):
-        self.log.debug("Checking for changes needed by %s:" % change)
-        # Return true if okay to proceed enqueing this change,
-        # false if the change should not be enqueued.
-        if not hasattr(change, 'needs_changes'):
-            self.log.debug("  Changeish does not support dependencies")
-            return True
-        if not change.needs_changes:
-            self.log.debug("  No changes needed")
-            return True
-        changes_needed = []
-        # Ignore supplied change_queue
-        with self.getChangeQueue(change) as change_queue:
-            for needed_change in change.needs_changes:
-                self.log.debug("  Change %s needs change %s:" % (
-                    change, needed_change))
-                if needed_change.is_merged:
-                    self.log.debug("  Needed change is merged")
-                    continue
-                with self.getChangeQueue(needed_change) as needed_change_queue:
-                    if needed_change_queue != change_queue:
-                        self.log.debug("  Change %s in project %s does not "
-                                       "share a change queue with %s "
-                                       "in project %s" %
-                                       (needed_change, needed_change.project,
-                                        change, change.project))
-                        return False
-                if not needed_change.is_current_patchset:
-                    self.log.debug("  Needed change is not the "
-                                   "current patchset")
-                    return False
-                if self.isChangeAlreadyInQueue(needed_change, change_queue):
-                    self.log.debug("  Needed change is already ahead "
-                                   "in the queue")
-                    continue
-                if self.pipeline.source.canMerge(needed_change,
-                                                 self.getSubmitAllowNeeds()):
-                    self.log.debug("  Change %s is needed" % needed_change)
-                    if needed_change not in changes_needed:
-                        changes_needed.append(needed_change)
-                        continue
-                # The needed change can't be merged.
-                self.log.debug("  Change %s is needed but can not be merged" %
-                               needed_change)
-                return False
-        if changes_needed:
-            return changes_needed
-        return True
-
-    def getFailingDependentItems(self, item):
-        if not hasattr(item.change, 'needs_changes'):
-            return None
-        if not item.change.needs_changes:
-            return None
-        failing_items = set()
-        for needed_change in item.change.needs_changes:
-            needed_item = self.getItemForChange(needed_change)
-            if not needed_item:
-                continue
-            if needed_item.current_build_set.failing_reasons:
-                failing_items.add(needed_item)
-        if failing_items:
-            return failing_items
-        return None
diff --git a/zuul/source/__init__.py b/zuul/source/__init__.py
index 610ae6e..bb79e9d 100644
--- a/zuul/source/__init__.py
+++ b/zuul/source/__init__.py
@@ -31,7 +31,6 @@
         self.source_config = source_config
         self.sched = sched
         self.connection = connection
-        self.projects = {}
 
     @abc.abstractmethod
     def getRefSha(self, project, ref):
diff --git a/zuul/source/gerrit.py b/zuul/source/gerrit.py
index 883d77a..e1a137a 100644
--- a/zuul/source/gerrit.py
+++ b/zuul/source/gerrit.py
@@ -16,7 +16,7 @@
 import re
 import time
 from zuul import exceptions
-from zuul.model import Change, Ref, NullChange, Project
+from zuul.model import Change, Ref, NullChange
 from zuul.source import BaseSource
 
 
@@ -127,9 +127,7 @@
         pass
 
     def getProject(self, name):
-        if name not in self.projects:
-            self.projects[name] = Project(name)
-        return self.projects[name]
+        return self.connection.getProject(name)
 
     def getChange(self, event):
         if event.change_number: