我在apache2 error.log中找到了这条消息

[notice] caught SIGWINCH,shutting
down gracefully

另外我注意到当apache停止响应时,apache2的进程ID大约为12000.

更新

正如您所指出的,捕获的SIGWINCH是apache服务重新启动的通知.我和最大客户一起玩,并保持活力.我将MaxClients设置得太低,所以我得到了“服务器达到MaxClients设置,考虑提高MaxClients设置”错误,但修复了这个问题.

关于PID,我的安装已经安装了prefork module,所以在达到MaxRequestPerChild之后,它会回收子进程.这就是PID定期上升的原因.仍然没有弄清楚为什么一段时间后apache停止响应.

同时将尝试上升MaxRequestPerChild,以便PID不会快速达到PID max.当前限制是32768(这是新debian和ubuntu安装的标准).

这里有更多来自日志：

[Fri Apr 24 01:48:56 2009] [notice]
caught SIGWINCH,shutting down
gracefully

[Fri Apr 24 01:50:07 2009] [notice]
Apache/2.2.8 (Ubuntu)
PHP/5.2.4-2ubuntu5.3 with
Suhosin-Patch configured — resuming
normal operations

[Fri Apr 24 17:13:35 2009] [error]
[client 195.70.62.131] client sent
HTTP/1.1 request without hostname (see
RFC2616 section 14.23):
/w00tw00t.at.ISC.SANS.DFind:)

[Fri Apr 24 17:36:00 2009] [error]
[client 212.188.33.4] client sent
HTTP/1.1 request without hostname (see
RFC2616 section 14.23):
/w00tw00t.at.ISC.SANS.DFind:)

[Sat Apr 25 20:05:07 2009] [error]
[client 84.243.222.12] Invalid URI in
request GET HTTP/1.1 HTTP/1.1

[Sat Apr 25 20:05:12 2009] [error]
[client 84.243.222.12] script not
found or unable to stat:
/usr/lib/cgi-bin/twiki

[Sat Apr 25 20:05:12 2009] [error]
[client 84.243.222.12] script not
found or unable to stat:
/usr/lib/cgi-bin/wiki

[Sat Apr 25 20:05:12 2009] [error]
[client 84.243.222.12] script not
found or unable to stat:
/usr/lib/cgi-bin/wikis

[Sat Apr 25 21:46:46 2009] [error]
[client 211.68.23.167] Invalid URI in
request GET HTTP/1.1 HTTP/1.1

[Sun Apr 26 06:13:47 2009] [error]
[client 86.39.154.89] client sent
HTTP/1.1 request without hostname (see
RFC2616 section 14.23):
/w00tw00t.at.ISC.SANS.DFind:)

[Sun Apr 26 06:53:07 2009] [notice]
Graceful restart requested,doing
restart