nginx报错提示：
*963623 recv() failed (104: Connection reset by peer) while reading response header from upstream ..
php-fpm.log报错提示：
WARNING: [pool www] child 10559 exited on signal 11 (SIGSEGV) after 0.504455 seconds from start ..
解决：(服务器出现502错误 可能进程过多导致)
修改 php-fpm.conf pm.max_children 设置的尽可能高一些
pm = dynamic
pm.max_children = 60
pm.start_servers = 30
pm.min_spare_servers = 30
pm.max_spare_servers = 60
重启php-fpm即可 。