On Wed, May 23, 2012 at 1:35 AM, Bongjae Chang <bongjae.ch...@gmail.com> wrote: > Hi all, > > When I tested mod_proxy + mod_proxy_balancer + (mod_proxy_ajp or > mod_proxy_http) with worker mpm, I always met CLOSE_WAIT state in apache > proxy side. > > I tested the following scenario. > > - Sending a request at the browser -> apache, mod proxy -> ajp or http java > server(1) > - Normally, browser received the response correctly and the connection state > was ESTABLISHED. > - And java server closed the ajp or http connection with timeout(Or > terminate java server forcibly). > - Then apache proxy machine always had the CLOSE_WAIT state about the > connection. > > It seemed that the apache proxy modules did not try to close the invalid > socket which had been already closed at the peer side(the backend java > server side). > > Perhaps is it already the known issue?
I believe this is normal. Apache keeps a pool of connections to the backend to re-use. There isn't an active thread going through all of the connections looking to see if they have been closed by the peer. The proxy module will check the state of a connection after grabbing it from a resource pool before it re-uses it so the connection in close_wait will eventually get closed and re-opened. Worse case, the number of close_wait connections would be capped at an upper limit based on your configs and your upstream server. Sridhar > > Please give me some advice if I am misunderstanding something. > > Thanks! > > -- > apache version: 2.4.2 > backend java server: grizzly http/ajp, playframework(maybe it uses netty) > os: Apache(Linux 2.6.18 x86_64), BackendServer(MacOs) > -- > > Regards, > Bongjae Chang
