Author: vinchen
Revision Date: 2012-02-15 10:09:43 UTC

fix the stuck problem when the clients' concurrency too much

  While doing stress testing, 5000 connections execute a short query through proxy constantly，the proxy would have no response after a while. If strace the proxy process, and all the event threads are always logged like this :
      sendto(4, ".", 1, 0, NULL, 0 <unfinished ...>

  The problem come from the function chassis_event_add, and there are too much event when the clients' concurrency too much.
  Now I modified the implement of chassis_event_add by using random num to determin the handle thread's event_base. Moreover, the event base of libevent must be thread-safe.
  So the proxy should depend on libevent which version no less than 2.0(event base is thread safe https://raw.github.com/libevent/libevent/patches-2.0/whatsnew-2.0.txt).

  The problem is critical, and see also in
 http://bugs.mysql.com/bug.php?id=63908&error=no
 http://forums.mysql.com/read.php?146,433299,433299#msg-433299