"com.sun.tools.attach.AgentLoadException: Agent JAR not found or no Agent-Class attribute" using AdoptOpenJDK 16

[Pieter12345]

Using AdoptOpenJDK 16 on Windows 10, I'm getting the following exception after selecting the Java process that I wish to monitor:

Sampling set to stop in 5 seconds.
Starting a server on /0.0.0.0:23000...
Once the server starts (shortly), visit the URL in your browser.
Note: The longer you wait before using the output of that webpage, the more accurate the results will be.
com.sun.tools.attach.AgentLoadException: Agent JAR not found or no Agent-Class attribute
        at jdk.attach/sun.tools.attach.HotSpotVirtualMachine.loadAgent(HotSpotVirtualMachine.java:159)
        at jdk.attach/com.sun.tools.attach.VirtualMachine.loadAgent(VirtualMachine.java:538)
        at com.sk89q.warmroast.WarmRoast.connect(WarmRoast.java:122)
        at com.sk89q.warmroast.WarmRoast.main(WarmRoast.java:327)

Additional information:
AdoptOpenJDK 8 has a jre/lib/management-agent.jar whereas some Java versions later, this jre directory no longer exists and JAVA_HOME now points directly to the JDK directory that no longer contains such a management-agent.jar file. This is referenced here.

[ProsperCraft]

I think this may be the same, I am getting this with OpenJDK 64-Bit Server VM 21.9 (build 17+35, mixed mode, sharing)

`
Attaching to PID 3679...
[0.438s][warning][os,thread] Failed to start thread - pthread_create failed (EAGAIN) for attributes: stacksize: 1024k, guardsize: 4k, detached.
[0.513s][warning][os,thread] Failed to start thread - pthread_create failed (EAGAIN) for attributes: stacksize: 1024k, guardsize: 0k, detached.

Starting a server on /0.0.0.0:22000...
Once the server starts (shortly), visit the URL in your browser.
Note: The longer you wait before using the output of that webpage, the more accurate the results will be.
com.sun.tools.attach.AgentLoadException: Agent JAR not found or no Agent-Class attribute
at jdk.attach/sun.tools.attach.HotSpotVirtualMachine.loadAgent(HotSpotVirtualMachine.java:160)
at jdk.attach/com.sun.tools.attach.VirtualMachine.loadAgent(VirtualMachine.java:538)
at com.sk89q.warmroast.WarmRoast.connect(WarmRoast.java:122)
at com.sk89q.warmroast.WarmRoast.main(WarmRoast.java:327)

`

[Pieter12345]

@ProsperCraft This indeed is caused by the same issue, being that a jar file that is being depended on is no longer available on JDK 16. Developers haven't responded for months now, so he only solution I see is to use another JVM profiler/sampler that is compatible with the more recent versions of Java. I do however like the simplicity of Warmroast, so I do plan on switching back if they do a compatibility update.

[ProsperCraft]

Did you find a working alternative for headless linux?

[Pieter12345]

Using Linux as a client, SSH'ing into your server with the -X option works to open the VisualVM GUI through SSH, but I haven't been able to get this working with a Windows machine as a client using WSL.