Include internal gearman server in docs
Change-Id: I668206d7a07f665309ca392a8e5f1702c278c47e
diff --git a/doc/source/launchers.rst b/doc/source/launchers.rst
index 832321c..cefd582 100644
--- a/doc/source/launchers.rst
+++ b/doc/source/launchers.rst
@@ -38,10 +38,16 @@
multiple Jenkins masters).
In order for Zuul to run any jobs, you will need a running Gearman
-server. The latest version of gearmand from gearman.org is required
-in order to support canceling jobs while in the queue. The server is
-easy to set up -- just make sure that it allows connections from Zuul
-and any workers (e.g., Jenkins masters) on port 4730, and nowhere else
+server. Zuul includes a Gearman server, and it is recommended that it
+be used as it supports the following features needed by Zuul:
+
+* Canceling jobs in the queue (admin protocol command "cancel job").
+* Strict FIFO queue operation (gearmand's round-robin mode may be
+ sufficient, but is untested).
+
+To enable the built-in server, see the ``gearman_server`` section of
+``zuul.conf``. Be sure that the host allows connections from Zuul and
+any workers (e.g., Jenkins masters) on TCP port 4730, and nowhere else
(as the Gearman protocol does not include any provision for
authentication.