Tomcat threads != JVM threads?

Question

The Tomcat Manager reports a different thread count than ThreadMXBean. The number of threads reported by ThreadMXBean is the same as the number of threads reported in the YourKit profiler as well. Is there a difference between Tomcat threads and JVM threads?

Line from Tomcat Manager:
Max threads: 200 Current thread count: 7 Current thread busy: 3

ManagementFactory.getThreadMXBean().getThreadCount():
38

Answer 1

Tomcat thread are request processing threads, and does not count other thread that the application may have started.

For a better look on what those other thread are, take a look at Thread.getAllStackTraces().

Answer 2

According to the javadocs, ManagementFactory.getThreadMXBean().getThreadCount():

Returns the current number of live threads including both daemon and non-daemon threads.

Therefore, the JVM could very well have 38 different threads going (mostly in the background). Tomcat makes a new thread for each request (so that it can have concurrent communication). It would make sense that these two numbers could differ.