I have Apache httpd with mod_jk. I have issue with killed connections after long idling period: Apache stops to respond and each HTTP request hangs for 15 minutes. I tried turn off mod_jk connection pooling (with DisableReuse) and the issue disappears.
In the Tomcat documentation it is written:
Using this option will have a strong performance penalty for Apache and Tomcat. Use this only as a last resort in case of unfixable network problems. If a firewall between Apache and Tomcat silently kills idle connections, try to use the worker attribute socket_keepalive in combination with an appropriate TCP keepalive value in your OS.
I tried to use socket_keepalive=true, it became better, but still sometimes HTTP request hangs for 15m.
So it seems like without socket_keepalive 90% of connections are dead, with socket_keepalive 10%, with DisableReuse 0%.
The OS is RedHat Enterprise 6.5. What is appropriate TCP keepalive value? and How it should be configured in my OS to make socket_keepalive works properly?