Linux version 2.6.8 服务器经常出现Too many open files 错误！需要调整一下Linux操作系统的 打开文件的最大句柄数。
要永久生效修改：/etc/security/limits.conf文件
在文件最后加上以下信息：
* - nofile 65536
以上语句表示,每个用户打开文件的个数为65536个
修改文件：/etc/sysctl.conf
在文件最后一行加上:
fs.file-max=65536
重启服务器后运行: ulimit -a
[root@redhat ~]# ulimit -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
file size (blocks, -f) unlimited
pending signals (-i) 1024
max locked memory (kbytes, -l) 32
max memory size (kbytes, -m) unlimited
open files (-n) 65536
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
stack size (kbytes, -s) 10240
cpu time (seconds, -t) unlimited
max user processes (-u) 16384
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited
以上红色字体为修改好的 最大打开文件个数！
临时增大 open files的个数可以运行命令: ulimit -n 65536
以上是解决方案之一，我们可以在apache的官方网站上查询到：
you may have a too low ulimit setup. It defaults to 1024, and each time you open a socket, that eats a file descriptor
You have options, though :
> - either you increase this ulimit, or set it to unlimited,
> - or you lower the tcp-time-wait value so that the sockets are closed faster.
故另外的一个方法就是减少操作系统 socket连接的等待时间
详细解决方案：http://mina.apache.org/mina-project/faq.html
In Windows, the default TIME_WAIT timeout is 4 minutes, in Linux it is 60 seconds.
在windows TIME_WAIT的缺省值是4 minutes，在Linux中时60秒；
修改方法如下：
Change the timeout in Windows(windows的更改方法，改为30-300秒)
- Run regedit to start the Registry Editor
- Locate the following key: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\tcpip\Parameters
- Add a new value named TcpTimedWaitDelay asa decimal and set the desired timeout in seconds (30-300)
- Reboot
Change the timeout in Linux(Linux的更改方法，改为30s)
-
Update the configuration value by running (30 seconds used in the example)
-
Restart the networking component, for example by running
echo 30 > /proc/sys/net/ipv4/tcp_fin_timeout
/etc/init.d/networking restart
or
service network restart