How to kill a java thread using VisualVM or using a unix command?

Question

I m using windows 7 OS. I have around 6 threads in my application. For the purpose of testing the alerts to check the health of the threads, i need to kill the thre

Answer 1

It's not true. You can always attach to the JVM process with GDB and do a call pthread_kill if you know the thread id. You only need to translate from the java thread dump (do a kill -3) which gives you a hex id, (native id), then look into the list of threads in GDB (info threads) and locate the real thread id.

This is proven to work.

Answer 2

As Peter says, you can't do this safely. Indeed on some platforms Thread.kill is not even implemented. However:

• If this is just for testing, a unit test that called Thread.kill would be reasonable ... assuming it worked on the test platforms where it needed to work. (A "loud" comment in the source code would be in order to help people porting the unit test ...)

• Another alternative is to add some code to the thread runnable that allows your unit tests to tell it to die. If the thread code needs to be (almost) production code for this to work, you could create a subclass that overrides something so that it "breaks" in a way that suits your purposes ... for testing. In fact, this approach allows you to cause the threads "break" in controlled ways, potentially allowing you to test different aspects of your alerting code.

Answer 3

Wait for some time in the thread and kill the thread in the code - simple way.

Answer 4

As mentioned in a previous post by buzz3791, it works by using jdb. However the change that I noticed is, you can't kill the thread, but you can interrupt or suspend the thread.

#jdb -attach 50100

threads --This will show all threads running on the jvm under Groups and Reference Handler section.

Groups	Reference Handler
:(com.orientechnologies.orient.server.network.protocol.binary.ONetworkProtocolBinary)0x36c1:	OrientDB (/xxx.xxx.xxx.xxx:123) <- BinaryClient (/xxx.xxx.xxx.xxx:678)

thread 0x36c1-- This will be the thread id that can be picked from one of the threads in the thread that you wish to kill/interrupt and run this interrupt 0x36c1

OrientDB (/xxx.xxx.xxx.xxx:123) <- BinaryClient (/xxx.xxx.xxx.xxx:678)[1] interrupt 0x36c1

you can try multiple times the same interrupt command and if it is already interrupted, it will show that the thread id is invalid. Thus you know that the thread is killed, this can be verified by looking at the stack trace and confirmed.

Tested this on the OrientDB database server with jdk 8 and it works.

Answer 5

In java you can not kill the like unix . Either you can interrupt the tread in java or you can kill the process in unix .

Answer 6

You can't do it from outside (OS or debugger), you'll have to write your own Thread watchdog that can interact with the user and kill the thread you want.

Try to look here for how to handle signals with java