Hello,

I have two servers for my web application. The first is for web, on this server is running nginx+php-fpm from dotdeb repository. On the second one is latest MariaDB 10.0.4 server.

Load on DB server is fine and work well. CPU is used only for 25%. Webserver is about 50%.

In netstat output i see many TIME_WAIT with source address 127.0.0.1:9000 <- This is from PHP-FPM. Web is too slow.
I have one warning: WARNING: [pool www] server reached max_children setting (1024), consider raising it . About 75% visitors have 502 Bad Gateway. When I increase max_children on 10 000, in a few second are all used. But I think, 1024 is fine. In netstat from my web server to database server are all connections ESTABLISHED.

This is my FPM config:
pm = ondemand
pm.max_children = 1024
pm.start_servers = 200
pm.min_spare_servers = 50
pm.max_spare_servers = 512
pm.process_idle_timeout = 10s;
pm.max_requests = 0

My sysctl.conf on both servers:
net.ipv4.tcp_fin_timeout = 1
net.ipv4.tcp_tw_recycle = 1
net.core.rmem_max = 16777216
net.core.rmem_default = 16777216
net.core.netdev_max_backlog = 262144
net.core.somaxconn = 262144
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_orphans = 262144
net.ipv4.tcp_max_syn_backlog = 262144
net.ipv4.tcp_synack_retries = 2
net.ipv4.tcp_syn_retries = 2
net.ipv4.ip_local_port_range = 1024 65535
fs.file-max = 70000

On my website is about 75 000 online visitor.

Thank you.