Install4j: Is is possible to configure an install4j launcher to respond to kill -3 and generate a thread dump?

Question

I would like to automatically create a thread dump as part of a log collection script I have written.

I know that it is possible to generate a thread dump using jstack or kill -3 . The customer running the log collection script will only have a JRE installed so jstack is not an option.

If I use jstack and the pid of the JVM that the install4j launcher creates I get the thread dump...however invoking kill -3 with the same pid generates no output. I am currently directing both stderror and stdout to files using the install4j launcher configuration.

This is a linux launcher that is configured with the service option.

FWIW...I have tried not directing the output and also running my application as a console program instead of a service and none of these allow 'kill -3' to work.

I'm using install4j 6.0

Lastly, I do not want to use -XX:+UnlockDiagnosticVMOptions -XX:+LogVMOutput -XX:LogFile=dump.log because of the unknown overhead it might create.

Any help would be appreciated!

Answer 1

I would suggest to use the ThreadMXBean to get this information programmatically in the same process rather than use signal handlers from another process. The API documentation is at

http://docs.oracle.com/javase/8/docs/api/java/lang/management/ThreadMXBean.html

Here's a full example of how to use this MBean.

In that way you can write the information explicitly to wherever you want it to go.