nginx 出错:socket() failed (24: Too many open files) while connecting to upstream

1. 错误描述

通过nginx负载两个节点的rabbitmq
当用java代码创建超过500个连接时(我的机器默认只能创建这么多)，出现错误：

com.rabbitmq.client.ShutdownSignalException: connection error
java.net.SocketException: Software caused connection abort: recv failed

查看nginx日志/var/log/nginx/error.log，发现错误
socket() failed (24: Too many open files) while connecting to upstream

解决

1. 修改linux打开文件句柄数，编辑vi /etc/security/limits.conf，添加

<domain>      <type>  <item>         <value>
*             soft   nofile          204800
*             hard   nofile          204800

2. 修改nginx打开文件数, 编辑nginx.conf，添加worker_rlimit_nofile值

worker_processes  1;
worker_rlimit_nofile 20480;

重启nginx后问题解决