improved explanation of "max_fsm_queue" option; included this option in ejabberd...

diff --git a/doc/guide.tex b/doc/guide.tex
index f8c00fdd1e5b28637a1d3bcafa469057a5a78132..c3657c9ae4d3f9bd0fcb706ed052dd6b2d156bac 100644 (file)
--- a/doc/guide.tex
+++ b/doc/guide.tex
@@ -881,7 +881,15 @@ This is a detailed description of each option allowed by the listening modules:
     The option can be defined in \term{ejabberd.cfg}, expressing the time
     in seconds: \verb|{http_poll_timeout, 300}.|
   \titem{\{max\_fsm\_queue, Size\}}
-    This option specifies the maximum number of elements in the queue of the FSM.
+    This option specifies the maximum number of elements in the queue of the FSM
+    (Finite State Machine).
+    Roughly speaking, each message in such queues represents one XML
+    stanza queued to be sent into its relevant outgoing stream. If queue size
+    reaches the limit (because, for example, the receiver of stanzas is too slow),
+    the FSM and the corresponding connection (if any) will be terminated
+    and error message will be logged.
+    The reasonable value for this option depends on your hardware configuration.
+    However, there is no much sense to set the size above 1000 elements.
     This option can be specified for \term{ejabberd\_service} and
     \term{ejabberd\_c2s} listeners,
     or also globally for \term{ejabberd\_s2s\_out}.
@@ -969,7 +977,15 @@ There are some additional global options that can be specified in the ejabberd c
   The maximum allowed delay for retry to connect after a failed connection attempt.
   Specified in seconds. The default value is 300 seconds (5 minutes).
   \titem{\{max\_fsm\_queue, Size\}}
-    This option specifies the maximum number of elements in the queue of the FSM.
+    This option specifies the maximum number of elements in the queue of the FSM
+    (Finite State Machine).
+    Roughly speaking, each message in such queues represents one XML
+    stanza queued to be sent into its relevant outgoing stream. If queue size
+    reaches the limit (because, for example, the receiver of stanzas is too slow),
+    the FSM and the corresponding connection (if any) will be terminated
+    and error message will be logged.
+    The reasonable value for this option depends on your hardware configuration.
+    However, there is no much sense to set the size above 1000 elements.
     This option can be specified for \term{ejabberd\_service} and
     \term{ejabberd\_c2s} listeners,
     or also globally for \term{ejabberd\_s2s\_out}.

diff --git a/src/ejabberd.cfg.example b/src/ejabberd.cfg.example
index 93ea7bb47782773e16d91cd99b0bbadb37215f6e..da46b786f04b96e83a7c2592cb85da1e1268def6 100644 (file)
--- a/src/ejabberd.cfg.example
+++ b/src/ejabberd.cfg.example
@@ -343,6 +343,12 @@
 %%
 {shaper, fast, {maxrate, 50000}}.
 
+%%
+%% This option specifies the maximum number of elements in the queue
+%% of the FSM. Refer to documentation for details.
+%%
+{max_fsm_queue, 1000}.
+
 
 %%%.   ====================
 %%%'   ACCESS CONTROL LISTS