In a production system, which is running 3 Tomcat webapps, we recently noticed that Tomcat crashed because of thread leaking. Two of the three webaps are interplaying with each other, and I would like to find out which one of the 2 components is causing this thread build-up.

**Question:** What is a good way/tool to find out which of the 3 webapps has thread leakage?

My java skills are very rusty. I am not very familiar with Tomcat, and discovering as I go along.
I launched `jconsole` to find out about the thread leak. I am reluctant to install additional (or non-default) tools to troubleshoot this, as this is a production system.

In the jconsole screenshot below, you can see the thread count grows; the Tomcat/catalina process halted at 08:52, a couple of minutes after the thread count maxed out at 893 threads.

[![jconsole](https://i.stack.imgur.com/QG7QE.png)](https://i.stack.imgur.com/QG7QE.png)

Per request, 

* the `Connector` element: `<Connector port="8009" protocol="AJP/1.3" redirectPort="8443" maxThreads = "600" minSpareThreads = "150" acceptCount = "150" connectionTimeout = "30000" />`
* by "Tomcat crashed", I mean that no more events are logged into the `catalina.log` file, as well as in none of the log files of the 3 webapps. Only the underlying apache is logging events, with HTTP 500 errors.