2019/07/25 08:31:31 [crit] 15929#15929: accept4() failed (24: Too many open files)
2019/07/25 08:31:31 [crit] 15930#15930: accept4() failed (24: Too many open files)
2019/07/25 08:31:31 [crit] 15930#15930: accept4() failed (24: Too many open files)
2019/07/25 08:31:31 [crit] 15930#15930: accept4() failed (24: Too many open files)
2019/07/25 08:31:31 [crit] 15930#15930: accept4() failed (24: Too many open files)
2019/07/25 08:31:31 [crit] 15930#15930: accept4() failed (24: Too many open files)
2019/07/25 08:31:31 [crit] 15930#15930: accept4() failed (24: Too many open files)
2019/07/25 08:31:31 [crit] 15930#15930: accept4() failed (24: Too many open files)
2019/07/25 08:31:31 [crit] 15930#15930: accept4() failed (24: Too many open files)
2019/07/25 08:31:31 [crit] 15930#15930: accept4() failed (24: Too many open files)
2019/07/25 08:31:31 [crit] 15930#15930: accept4() failed (24: Too many open files)
2019/07/25 08:31:31 [crit] 15930#15930: accept4() failed (24: Too many open files)
2019/07/25 08:31:31 [crit] 15930#15930: accept4() failed (24: Too many open files)

 

注意：修改 nginx 的 max open files 有个前提，就是你已经修改好了系统的 max open files.
修改系统中的 /etc/security/limits.conf文件中
 sudo vim /etc/security/limits.conf #在最后添加如下两行
* soft nofile 65535
* hard nofile 65535
这是网上搜了很多教程，但是到此还是无法解决问题

上面修改了系统的 max open files，并不代表nginx的
先查看 nginx 的 ulimits： 
grep 'open files' /proc/$( cat /var/run/nginx.pid )/limits

　　

　

发现nginx 的 max open files 并没有变化

修改 nginx.service
sudo vim /lib/systemd/system/nginx.service # （仅适用于 ubuntu）
添加如下：
[Service]
LimitNOFILE=65535
重启服务：
sudo systemctl daemon-reload
修改 nginx.conf，
添加：以下两点
worker_rlimit_nofile 65535; # (has to be smaller or equal to LimitNOFILE set above)
events {
    worker_connections  65535;
}
重启 nginx:
sudo systemctl restart nginx

然后再去查看nginx的 max open files，看看是不是我们设置的65535
grep 'open files' /proc/$( cat /var/run/nginx.pid )/limits
到此就修改nginx的max open files结束。

但是如果你已经把nginx 的max open files值改的很大了，但是还是会出现Too many open files 的错误，那说明你后端服务器处理请求的速度太慢了，或是 并发太高了。