vps又挂了一下

今天vps又挂了一下，不是502了，直接没有反应，忘了 测试nginx有没有反映了。应该测试一下html文件能不能打开，看这次是php-cgi的问题还是nginx的问题，我直接重启的vps，这样问题就消失了。考虑到问题可能还会再现，所以依然百度了一下问题，这次看别人把logs都贴出来，我也查看一下自己的log文件。
nginx的logs里是四月份的错误，没有这几天的，说明nginx一直运行很好，虽然时不时的出个502，在看php-fpm的log，可不得了，它一直记录着自己的错误，我竟然一直没有看，截一下今天的部分错误

Jun 15 08:54:20.173202 [WARNING] fpm_children_bury(), line 215: child 13876 (pool default) exited on signal 15 SIGTERM after 1501.162766 seconds from start
Jun 15 08:54:20.173240 [WARNING] fpm_children_bury(), line 215: child 13877 (pool default) exited on signal 15 SIGTERM after 1501.161380 seconds from start
Jun 15 08:54:20.173277 [WARNING] fpm_children_bury(), line 215: child 13879 (pool default) exited on signal 15 SIGTERM after 1501.160255 seconds from start
Jun 15 08:54:20.173314 [WARNING] fpm_children_bury(), line 215: child 13880 (pool default) exited on signal 15 SIGTERM after 1501.159244 seconds from start
Jun 15 08:54:20.173624 [WARNING] fpm_children_bury(), line 215: child 13891 (pool default) exited on signal 15 SIGTERM after 1501.143989 seconds from start
Jun 15 08:54:20.173661 [WARNING] fpm_children_bury(), line 215: child 13892 (pool default) exited on signal 15 SIGTERM after 1501.142966 seconds from start
Jun 15 08:54:20.173684 [NOTICE] fpm_got_signal(), line 48: received SIGCHLD
Jun 15 08:54:20.173696 [NOTICE] fpm_got_signal(), line 48: received SIGCHLD
Jun 15 08:54:20.173705 [NOTICE] fpm_got_signal(), line 48: received SIGCHLD
Jun 15 08:54:20.173714 [NOTICE] fpm_got_signal(), line 48: received SIGCHLD
Jun 15 08:54:20.173798 [NOTICE] fpm_got_signal(), line 48: received SIGCHLD
Jun 15 08:54:20.173807 [NOTICE] fpm_got_signal(), line 48: received SIGCHLD
Jun 15 08:54:20.178277 [NOTICE] fpm_got_signal(), line 48: received SIGCHLD
Jun 15 08:54:20.178339 [WARNING] fpm_children_bury(), line 215: child 13885 (pool default) exited on signal 15 SIGTERM after 1501.160037 seconds from start
Jun 15 08:54:20.191719 [NOTICE] fpm_got_signal(), line 48: received SIGCHLD
Jun 15 08:54:20.191802 [WARNING] fpm_children_bury(), line 215: child 13882 (pool default) exited on signal 15 SIGTERM after 1501.175649 seconds from start
Jun 15 08:54:20.191814 [NOTICE] fpm_pctl_exit(), line 81: exiting, bye-bye!
Jun 15 08:54:21.098436 [NOTICE] fpm_unix_init_main(), line 284: getrlimit(nofile): max:51200, cur:51200
Jun 15 08:54:21.098660 [NOTICE] fpm_event_init_main(), line 88: libevent: using epoll
Jun 15 08:54:21.098735 [NOTICE] fpm_init(), line 52: fpm is running, pid 19936
Jun 15 08:54:21.113242 [NOTICE] fpm_children_make(), line 352: child 19937 (pool default) started
Jun 15 08:54:21.114894 [NOTICE] fpm_children_make(), line 352: child 19938 (pool default) started
Jun 15 08:54:21.116288 [NOTICE] fpm_children_make(), line 352: child 19939 (pool default) started
Jun 15 08:54:21.117592 [NOTICE] fpm_children_make(), line 352: child 19940 (pool default) started
Jun 15 08:54:21.133599 [NOTICE] fpm_children_make(), line 352: child 19952 (pool default) started
Jun 15 08:54:21.134687 [NOTICE] fpm_children_make(), line 352: child 19953 (pool default) started
Jun 15 08:54:21.135713 [NOTICE] fpm_children_make(), line 352: child 19954 (pool default) started
Jun 15 08:54:21.135747 [NOTICE] fpm_event_loop(), line 107: libevent: entering main loop

参考了网上的内容，修改了一下东西，可是我基本上都已经做过了，
比如张宴的方法（加进程，加FastCGI的timeout时间）、做均衡等等，我在这儿http://www.5169.info/software/lnmp/ru-is-how-to-analyze-the-nginx-php-fpm-for-502-errors.html已经写过了
昨天新加进去的东西

ulimit –n

查看php打开文件数的限制，昨天修改的时候是1024，怎么会那么少呢？
打开/usr/local/webserver/php/etc/php-fpm.conf

vi /usr/local/webserver/php/etc/php-fpm.conf

修改

<value name="rlimit_files">65535</value>

其实我改为51200了，记得哪儿达不到65535 ,  51200比较保险点吧
打开/etc/security/limits.conf

vi /etc/security/limits.conf

加上

* soft nofile 51200
* hard nofile 51200

这儿限制一个进程能打开多少个文件（/etc/sysctl.conf 文件中的fs.file-max=XXX 限制系统一共能打开多少个文件 ）

最后我还发现我的php-fpm.conf中  request_terminate_timeout  是900s，当初怎么想的，好想这样改了以后，502少了

ulimit -SHn 51200
/usr/local/webserver/php/sbin/php-fpm restart

查看文件打开限制

ulimit –n

显示51200
重启php-fpm，不过我感觉不出来是否变好了，等时间的验证吧