Here are some of the timeouts already defined :

Under server wide nginx.conf :

keepalive_timeout 5;
send_timeout 150;

under specific vhost.conf :

proxy_send_timeout 100;
proxy_read_timeout 100;
proxy_connect_timeout 100;
fastcgi_connect_timeout 120;
fastcgi_send_timeout 300;
fastcgi_read_timeout 300;

Different values for timeouts are used so I can figured out which timeout was exactly triggered.

Below are some of the settings from sysctl.conf :

net.ipv4.ip_local_port_range = 1024 65500
net.ipv4.tcp_fin_timeout = 10
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_syn_retries = 6
net.core.netdev_max_backlog = 8192
net.ipv4.tcp_max_tw_buckets = 2000000
net.core.somaxconn = 4096
net.ipv4.tcp_no_metrics_save = 1
vm.max_map_count = 256000


Thanks!