近期用java写的email服务器经常出现 broken pipe 错误。 经查验
有可能是linux的线程机制会产生JVM出错的问题，特别是在连接高峰期间经常出现这样的问题，tomcat在linux下也出现类似情况。
解决办法是在环境变量中设置： _JAVA_SR_SIGNUM = 12 基本就可以解决。
在WIN环境变量中设置： _JAVA_SR_SIGNUM =12, 若Linux下用 export _JAVA_SR_SIGNUM =12, 基本就可以解决.
sun的解释：
－－posted by: cooper
Below is a clipping from Sun on working around JVM crashes under high
thread counts in the JVM 1.3 for Linux
On Linux, use a larger signal number for hotspot thread
suspension/resumption handler. The signal number being used is
specified by environment variable _JAVA_SR_SIGNUM. Setting it to a
number larger than SIGSEGV (11) will solve the problem. A good number
to use is 12, which is SIGUSR2. Using signal 16 to work around the
problem might have potential problems. So on tcsh, "setenv
_JAVA_SR_SIGNUM 12" can solve the problem.