An application running a lightly loaded Apache HTTPD 2.0 has occasionally had problems where one (or more?) of the Apache processes took 100% CPU. We currently run HTTPD 2.2, I we may have seen this with 2.2 as well. I'm not certain. In some cases, the CPU usage was such that it blocked all but console access to the Windows server hosting HTTPD. I have never been able to track down what can cause Apache to do this.
The environment is Apache HTTPD directly serving static content, using mod_rewrite but not much else custom configuration. HTTPD is talking to Apache Tomcat (5.x) via
Has anyone else encountered this and solved it? The workaround we installed is to limit each Apache HTTPD subprocess to a maximum number of requests with the following configuration:
where because the application uses HTTP/1.1, this is really more than 1000 requests per child process and more like 100,000 requests per child process.