I have a Web application built in PHP. The client is a standard html/js page viewed in the web browser. This client sends Ajax requests every minute to get its updates. This setup worked the same way since two years.
The logs tell me that one user seems not to have shut down his computer on Thursday, so the browser client was sending his requests over the Easter weekend without pause. This normally should be no problem, it is just the only odd thing I noticed trying to trace the problem. Around 4PM on Sunday the requests by this client as found in Apaches access.log abruptly stopped.
Around 6PM suddenly the app is not reachable anymore, as the maximum number of connections of Apache is reached. More than 400 connections by the IP of said client are in the state of CLOSE_WAIT.
I am now trying to understand how this could happen. There is no external database and only PHP on Apache2 used. Normally the handling of the tcp request should therefore not be an occuring problem, as they're out of the scope of the PHP application.
Thank you.