refer
    1、修改了nginx配置后,在nginx的sbin目录下执行nginx -t,测试通过没有问题,
    再执行nginx -s reload ,访问服务发现配置文件没有生效,
    2、查看nginx进程

    1. # ps -ef| grep nginx
    2. root       251     0  0 07:35 ?        00:00:00 nginx: master process openresty
    3. nobody     252   251  0 07:35 ?        00:00:02 nginx: worker process is shutting down
    4. nobody     277   251  0 07:36 ?        00:00:02 nginx: worker process is shutting down
    5. nobody     303   251  0 07:38 ?        00:00:02 nginx: worker process is shutting down
    6. nobody     327   251  0 07:54 ?        00:00:01 nginx: worker process is shutting down
    7. nobody     353   251  0 07:55 ?        00:00:00 nginx: worker process is shutting down
    8. nobody     380   251  0 07:56 ?        00:00:00 nginx: worker process is shutting down
    9. nobody     404   251  0 07:56 ?        00:00:01 nginx: worker process
    10. root       427    17  0 08:04 pts/1    00:00:00 grep --color=auto nginx

    发现很多shutting down

    3、尝试重启nginx才生效，shutting down的进程也没了

    1. nginx -s stop
    2. nginx

    原因分析:使用nginx -s reload 重启之后，旧的worker仍然会跑，新的请求会开新的worker,旧worker不再接受新链接，等所有连接结束后旧worker会退出，如果有长链接一直存在，那么将会一直用的是旧配置。