前端时间 在做压力测试，从日志上看 到FSM limit reached (<0.242.0>): {max_queue,1001}(ejabberd),因为没做详细记录，没重现。今天又出现了。
ERROR 日志
%%
%%{max_fsm_queue, 1000}.
=INFO REPORT==== 2010-11-03 15:56:37 ===
I(<0.1849.0>:ejabberd_http:137) : started: {gen_tcp,#Port<0.5767>}
=ERROR REPORT==== 2010-11-03 15:56:37 ===
FSM limit reached (<0.242.0>): {max_queue,1001}
=INFO REPORT==== 2010-11-03 15:56:37 ===
I(<0.243.0>:ejabberd_odbc:527) : Closing connection #Port<0.4266>: ok
打开ejabberd.cft配置文件 vi /etc/ejabberd/ejabberd.cfg看到
%%
%% This option specifies the maximum number of elements in the queue
%% of the FSM. Refer to the documentation for details.
%%
{max_fsm_queue, 1000}.
的配置信息
怀疑这里的问题，我干脆注释掉了，问题依旧。只好加大了 {max_fsm_queue, 1000000}.
加大后，日志不再抛出信息。
后来又查了一下官方文档
{max_fsm_queue, Size}
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
ejabberd_service and
ejabberd_c2s listeners, or also globally for
ejabberd_s2s_out. If the option is not specified for
ejabberd_service or
ejabberd_c2s listeners, the globally configured value is used. The allowed values are integers and ’undefined’. Default value: ’undefined’.
此选项指定在有限状态机队列中元素的最大数量。粗略地说，每个队列的消息，表示在这样一个XML节排队纳入其有关输出流发送。如果队列大小达到极限（因为，例如，节接收机太慢），有限状态机和相应的连接（如果有）将被终止，错误信息会被记录。此选项的合理值取决于你的硬件配置。但是，设置1000以上个元素的大小
没有多大意义
。此选项可指定ejabberd_service和ejabberd_c2s听众，或者也可以ejabberd_s2s_out全球。如果该选项不适合ejabberd_service或ejabberd_c2s听众指定，全球配置的值。允许的值是整数和'未定义'。默认值：'未定义'。
困惑的地 默认 undefined .到底是多少个？请高人指点
