[Bug] skywalking agent

[wangkang4]

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Apache SkyWalking Component

Java Agent (apache/skywalking-java)

What happened

java agent version：9.0.0
arthas：3.7.1
The arthas retransform command is used to hot-load the class file. A retransform error message is displayed. java.lang.UnsupportedOperationException: class redefinition failed: attempted to change superclass or interfaces

What you expected to happen

The arthas hot-load class file function is not affected.

How to reproduce

Anything else

No response

Are you willing to submit a pull request to fix on your own?

• Yes I am willing to submit a pull request on my own!

Code of Conduct

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

[wu-sheng]

duplicated reported.

[wu-sheng]

follow #11651

[wangkang4]

Hello, does skywalking support arthas' retransform command? After the configuration of agent.is_cache_enhanced_class and agent.class_cache_mode is enabled, the redefine command is successfully executed, but the retransform command fails. Using the jad command, you found that skywalking added properties and methods to the class.

[wu-sheng]

We don't support it officially. As you can see on #11651, someone may have an interest in doing as best as they can. You could try that PR version.

[lujiajing1126]

Hello, does skywalking support arthas' retransform command? After the configuration of agent.is_cache_enhanced_class and agent.class_cache_mode is enabled, the redefine command is successfully executed, but the retransform command fails. Using the jad command, you found that skywalking added properties and methods to the class.

IIRC, IS_CACHE_ENHANCED_CLASS flag has been removed since SkyWalking Agent 9.0

[wangkang4]

arthas' hot-load class file commands, such as redefine and retransform, are not currently supported by the services monitored by skywalking, right?

[wangkang4]

Hello, does skywalking support arthas' retransform command? After the configuration of agent.is_cache_enhanced_class and agent.class_cache_mode is enabled, the redefine command is successfully executed, but the retransform command fails. Using the jad command, you found that skywalking added properties and methods to the class.

IIRC, IS_CACHE_ENHANCED_CLASS flag has been removed since SkyWalking Agent 9.0

How to modify skywalking javaagent to support arthas hot load class command, is there a case code?

[lujiajing1126]

Hello, does skywalking support arthas' retransform command? After the configuration of agent.is_cache_enhanced_class and agent.class_cache_mode is enabled, the redefine command is successfully executed, but the retransform command fails. Using the jad command, you found that skywalking added properties and methods to the class.

IIRC, IS_CACHE_ENHANCED_CLASS flag has been removed since SkyWalking Agent 9.0

How to modify skywalking javaagent to support arthas hot load class command, is there a case code?

As you may notice in apache/skywalking-java#659, we are still working on this topic. I suppose after that PR, we may stabilize this feature.

Feel free to test this PR for your use cases. Feedback is welcome.

[wangkang4]

Is arthas' redefine and retransform commands not currently supported for modifying the target class? Because skywalking's javaagent adds a few new methods to the target class.

[wangkang4]

Hello, does skywalking support arthas' retransform command? After the configuration of agent.is_cache_enhanced_class and agent.class_cache_mode is enabled, the redefine command is successfully executed, but the retransform command fails. Using the jad command, you found that skywalking added properties and methods to the class.

IIRC, IS_CACHE_ENHANCED_CLASS flag has been removed since SkyWalking Agent 9.0

How to modify skywalking javaagent to support arthas hot load class command, is there a case code?

As you may notice in apache/skywalking-java#659, we are still working on this topic. I suppose after that PR, we may stabilize this feature.

Feel free to test this PR for your use cases. Feedback is welcome.

Why does a javaagent using skywalking generate so many classes with $? Using arthas's trace command, we looked at the call chain and found that the generated proxy classes were all executed.

[wu-sheng]

That is why your codes could be traced and monitored.
Your codes are changed by the agent.