Bug Report: Suspected WebappClassLoader Leak

[kelvinlukhee]

Brief Summary

We are currently using payara version 5.2022.5.

We noticed an increase in memory usage after each redeployment of our web application and thus we spent some time in investigating it. We captured the heap dump of the payara server after redeployment. We found that the instance of WebappClassLoader from the last deployment was not garbage collected, holding most of the resources with it.

We tried to find out which GC root was holding a reference to it and prevented the destruction of the classloader. The screenshot attached below shows our finding. It looks like a cached request in the DefaultWorkerThread's cache is holding a reference to the classloader. However, we have searched online and looked into the codes, and yet failed to find a way to tell it to evict the cache.

Expected Outcome

The old WebappClassLoader instance shall be garbage collected to recover the memory held by objects of the last instances

Current Outcome

The old WebappClassLoader instance remains alive and prevented the garbage collection of other objects.

Reproducer

To be provided later

Operating System

Centos 6.5

JDK Version

Oracle JDK 1.8.202

Payara Distribution

Payara Server Web Profile

[kalinchan]

Hi @kelvinlukhee,

It looks like you are running Payara Community 5 which is out of support.

Are able to test this issue on the current release of Community 6?

[github-actions]

Greetings,
It's been more than 5 days since we requested more information or an update from you on the details of this issue. Could you provide an update soon, please?
We're afraid that if we do not receive an update, we'll have to close this issue due to inactivity.

[github-actions]

Greetings,
It's been more than 5 days since this issue was identified as abandoned.
We have closed this issue due to inactivity, please feel free to re-open it if you have more information to share.