问题
Is there a possibility that kill -3 / quit PID prints nothing i.e. an empty thread dump? We heard a story from a support engineer and was wondering if some experts could validate.
This is on Java 6_26 on RHEL 5
回答1:
I have only seen this when the server redirects to stdout, like JBoss, and stdout has been redirected to /dev/null because whoever set up the server thought that everything going to stdout was already going to a named log file.
回答2:
The console output of JVM thread dump on some servers is redirected to a log file. In case of Tomcat Server it is usually Catalina.out.
回答3:
I have seen the behavior you describe in a standalone Java application (Oracle JDK 1.6.20+, Linux), but I can't tell how to reproduce this behavior consistently. It may have been after an OutOfMemoryError in one of the threads but I'm not sure any more.
I also think that what I got was not just an empty dump, but that the command actually froze and didn't return me to the shell until I pressed ctrl+C after waiting for a while. Either way, I'm sure that the behavior of jstack was exactly the same as of kill -3. When it happened, the app was in such bad shape that it didn't react to normal kill and only kill -9 worked on it. There were no redirections and under normal circumstances the app reacted to kill -3 as it should.
来源：https://stackoverflow.com/questions/9569723/no-threaddump-generated-on-kill-3