[emerg]: bind() to 0.0.0.0:80 failed (98: Address already in use) 问题思考？

正常运行时，即网页能够访问时：
[root@web1 ~]# ps -aux | grep nginx
Warning: bad syntax, perhaps a bogus '-'? See /usr/share/doc/procps-3.2.8/FAQ
www       1928  0.0  0.5  64560 21748 ?        S    10:29   0:00 nginx: worker process                                          
root     37826  0.0  0.0 103168   856 pts/0    S+   10:56   0:00 grep nginx


出现 [emerg]: bind() to 0.0.0.0:80 failed (98: Address already in use)
问题时：
[root@web2 sk]# ps -aux | grep nginx
Warning: bad syntax, perhaps a bogus '-'? See /usr/share/doc/procps-3.2.8/FAQ
root      1608  0.0  0.0  44548  1080 ?        Ss   10:48   0:00 nginx: master process /usr/local/nginx/sbin/nginx -c /usr/local/nginx/conf/nginx.conf
www       1609  0.0  0.5  64560 21276 ?        S    10:48   0:00 nginx: worker process                                          
root      1628  0.0  0.0 103168   856 pts/0    S+   10:56   0:00 grep nginx


然后测试其状态：
[root@web1 ~]# nginx -c /usr/local/nginx/conf/nginx.conf
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] still could not bind()


[root@web2 sk]# nginx -c /usr/local/nginx/conf/nginx.conf
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] still could not bind()


两个 web 服务器都被占用？那 web1 怎么能够访问？ web2 竟然不能


难道是 主进程 在干扰？
怎样解决？
网上说的是
kill -9 $PID --nginx 的 pid

没有用，我这里

突然就弄好了？

看来下次要好好观察