Tools to monitor java thread execution

Question

I\'ve a java web application running on an Tomcat server(Linux). In the production environment I\'m facing some performance issue. At random intervals the jsvc process on which

Answer 1

There's a Linux tool called "threadcpu" which measures the cpu usage of each thread. And in case of a Java thread it uses jstack to get and print the thread name.

http://www.tuxad.com/blog/archives/2018/10/01/threadcpu_-_show_cpu_usage_of_threads/index.html

Answer 2

VisualVM is what you're looking for. It ships with newer JDKs and allows you to monitor thread usage.

Answer 3

You can get a stacktrace dump for all threads in any Java application by sending it a QUIT signal.

 kill -QUIT [processId]

This will show up in the process' stdout.

Answer 4

Just my 2 cents but I'm wondering if you are not experimenting a memory issue the CPU peaks could be the GC activity. So while you're monitoring your tomcat with jconsole have a look to the memory tab and check if the heap usage is not going to high.

Answer 5

One relatively easy way to do this (which may or may not work for your case -- depends on how long the behavior occurs):

When your app exhibits the behavior you want to debug (in this case, 90-100% CPU use) use jstack on the process ID:

http://download.oracle.com/javase/6/docs/technotes/tools/share/jstack.html

to examine what threads are running and in what methods they occur. If you do that a few times, it may be relatively easy to spot the culprit call chain. You can then just debug the entrance to that chain.

It's not necessarily the best or most elegant method, but it's very easy to do and it may be all you need. I would start there. It's akin to the "printf is the best debugger I've ever used" philosophy.

Answer 6

Another tool for showing the top cpu-consuming threads is jvmtop