Tomcat中的多个Java进程

Question

I am working on a web-based application which is deployed in the Tomcat server. In our local dev enviroemt, when we start the Tomcat server it spawns only one java process which keeps running. However, an issue has been reported in production where the CPU usage for java process has gone up and there are multiple java processes which have been spawned.

There is no other java application running, so this must have been spawned from Tomcat itself. What is the reason that in our development enviroment there is only one java process while in production multiple java processes have been spawned by Tomcat and how to correct it.

Regards, Dev

Answer 1

Unlike Apache HTTPD, Tomcat doesn't spawn processes on its own (it uses multiple threads to serve multiple clients) so you should look elsewhere. For example, how do you deploy your application to the Tomcat. Could it be something like a buggy deployment script?

Also, what other applications run on this Tomcat container?

Answer 2

What you see are most likely multiple threads that the version of top or ps shows on the production box, while you don't see them on the local one.

In production you most likely face a much higher workload, so that requests are served in parallel, while on the local box Tomcat gets away with less threads.