Application may be blocked on reading TCP scocket I\/O\u00a0 when connection was dropped.\u00a0 It could take up to 2 hours for application to detect this disconnection without a separate thread monitoring network heatbeat(Application level heatbeat ) and TCP native keepalive enabled and tune.<\/p>\n
TCP keepalive is an optional feature and has to be explicitly enabled when creating a new sockets.\u00a0 Tune the following using sysctl and persist the change in \/etc\/sysctl.conf as well.<\/p>\n
net.ipv4.tcp_keepalive_time=10
\nnet.ipv4.tcp_keepalive_probes=2
\nnet.ipv4.tcp_keepalive_intvl=3<\/p>\n
The above means heatbeats will be sent every 10s. If no response received for the corresponding heartbeat, another heartbeat will be sent out every 3 sends.\u00a0 If 2 response (probes) missed, connection will be regarded as dropped and blocking I\/O will be signaled.\u00a0 Application thus get a chance to return from blocking I\/O and receive an error or exception for re-establish a new connection.<\/p>\n
Futher tuning can be done on tcp_user_timeout, fin-wait, fin-wait2, close-wait, for more details please read the following pages.<\/p>\n
Patching RMQ issue<\/a><\/p>\n “RabbitMQ Best Practices”<\/a><\/p>\n