[Bug] skywalking java agent consistently takes highly cpu spends

[JaydenHu6]

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• I had searched in the issues and found no similar issues.

Apache SkyWalking Component

Java Agent (apache/skywalking-java)

What happened

when app have lots of thread, SkywalkingAgent-5-JVMService-produce-0 thread takes highly cpu spends

My application has 8035 threads running on an 8 core machine and the SkywalkingAgent-5-JVMService-produce-0 thread consistently spends around 99.9% of the cpu.

it occurs in JVMService

What you expected to happen

I noticed that JVMService is scheduled every second, is it possible to schedule every 30s in default and can be configured in agent.config ?

How to reproduce

create lots of thread in your application，and type top -H -p ${pid} to see cpu spends. your can use arthas to find more details.

Anything else

No response

Are you willing to submit PR?

• Yes I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct

[JaydenHu6]

Besides, when my application have 3025 thread running on same machine, the SkywalkingAgent-5-JVMService-produce-0 thread consistently spends around 16.1% of the cpu.

[JaydenHu6]

I agree with your point of view, but more, now the collection frequency in JVMService is too high and fixed, it should be configured

[wu-sheng]

I don't think configuration would help a lot. What do you propose to config?

[JaydenHu6]

The JVMService-produce and JVMService-consume threads are scheduled once per second. The scheduling frequency is fixed. Can the scheduling frequency be modified by parameters?

[wu-sheng]

I mean for 5k threads, even do once per 30s, you service would still not be healthy. It would be stopped when read thread information.

[wu-sheng]

If we provide a config, it seems only to expose disable option, for permanently closing this metric.