Hi

We are using Liferay 6.2 EE with JBoss 7.1.1 as our Application Cluster with Apache Tomcat  Web Server at the top. We are experiencing frequent Application stability issues. All of a sudden the AJP Connections become very high & it keep increasing.

We've analyzed the thread dumps,

1. We found the dump is flooded with the below threads

ajp--0.0.0.0-8009-560 - priority:10 - threadId:0x00007f778c007800 - nativeId:0xefe5 - state:RUNNABLE

stackTrace:

java.lang.Thread.State: RUNNABLE

at java.net.SocketInputStream.socketRead0(Native Method)

at java.net.SocketInputStream.read(SocketInputStream.java:152)

at java.net.SocketInputStream.read(SocketInputStream.java:122)

at org.apache.coyote.ajp.AjpProcessor.read(AjpProcessor.java:1131)

at org.apache.coyote.ajp.AjpProcessor.readMessage(AjpProcessor.java:1213)

at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:451)

at org.apache.coyote.ajp.AjpProtocol$AjpConnectionHandler.process(AjpProtocol.java:445)

at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:930)

at java.lang.Thread.run(Thread.java:745)

It seems to be AJP thread leaks.

Also please note that we've the following settings applied in the standalone.xml of Application Servers (Two Application Server vm instance is running in the same cluster).