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https://issues.apache.org/jira/browse/MYFACES-4722?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17950047#comment-17950047
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Paul Pogonyshev commented on MYFACES-4722:
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I use Java 21 and WildFly 26. No idea about the exception you receive.
> I saw lots of remaining weak references in OL
This is expected. Weak references don't prevent GC on their own and I used them
to detect (and print) when a bean is GC'd. The code has flaws, of course, but I
only wanted to make it work, not polish. For comparison, it also creates
request-scoped beans, and those _are_ garbage-collected, unlike unscoped ones.
(This is exactly what we observed in the real application.)
> Memory leak when using unscoped managed beans
> ---------------------------------------------
>
> Key: MYFACES-4722
> URL: https://issues.apache.org/jira/browse/MYFACES-4722
> Project: MyFaces Core
> Issue Type: Bug
> Components: General
> Affects Versions: 2.3.11
> Environment: Linux + WildFly
> Reporter: Paul Pogonyshev
> Assignee: Volodymyr Siedlecki
> Priority: Major
> Attachments: image-2025-05-07-11-29-07-479.png,
> myfaces-memory-leak.tar.gz
>
>
> When a managed bean is instantiated by MyFaces, it gets registered in some
> deployment-global map. I'm not sure about the interface involved, on WildFly
> it boils down to `CachingWebInjectionContainer`. When the bean's scope
> (request, session, etc.) is closed, the bean is removed from this map.
> However, if the bean has no scope associated, it seems to never get removed,
> essentially leaking memory. If the bean is large or references lots of
> objects, this eventually leads to OOM situation. We have observed this in
> practice.
> I created a simple reproducer project. I only tested with MyFaces 2.3 and
> WildFly 26, but the bug might also be present in newer versions as well (it
> is simply not easy for me to test as I used the same setup as for our real
> project).
> To reproduce:
> * unpack the project;
> * build it (`./gradlew clean build`);
> * deploy on WildFly;
> * visit the page (sth. like
> `http://localhost:8080/myfaces-memory-leak/test.jsf`);
> * refresh about 10-20 times (depends on WildFly settings etc.);
> * eventually OOM is triggered.
> You also don't have to wait for OOM. If you check server output (stdout) you
> can see text like this:
> NEW MANAGED BEAN: request #0
> NEW MANAGED BEAN: unscoped #1
> NEW MANAGED BEAN: unscoped #2
> NEW MANAGED BEAN: request #3
> GARBAGE-COLLECTED: request #0
> NEW MANAGED BEAN: unscoped #4
> NEW MANAGED BEAN: unscoped #5
> NEW MANAGED BEAN: request #6
> GARBAGE-COLLECTED: request #3
> ...
> I.e. managed beans with request scope get allocated and then
> garbage-collected. However, beans without associated scope never get
> garbage-collected because they are still reachable in memory.
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