Tomcat & Apache: High CPU Usage

Summary: Tomcat running behing an Apache Frontend Server can cause high CPU Usage on the Java Process. Here are several approaches how to fix it.

Setup: Debian GNU/Linux, Java Runtime Environment (JRE) 1.6, Apache 2.2, Tomcat 6.0.29, mod_jk/mod_proxy

Effect: Accessing web applications directly through Tomcat doesn’t cause any problems. When accessing web applications through the Apache Frontend Server (forwarding requests by using mod_proxy), it took a few seconds and the cpu usage of the Java process went up to 99.9 %. Obviously, the combination of Apache and Tomcat is causing this problem. Continue reading Tomcat & Apache: High CPU Usage