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Posted to dev@jackrabbit.apache.org by "Julian Reschke (Jira)" <ji...@apache.org> on 2021/04/29 12:49:01 UTC

[jira] [Commented] (JCR-4674) Deadlock at ItemManager.getItem

    [ https://issues.apache.org/jira/browse/JCR-4674?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17335435#comment-17335435 ] 

Julian Reschke commented on JCR-4674:
-------------------------------------

[~hwe] - any news on this? Was this a config issue? If no, have you been able to collect more information?

> Deadlock at ItemManager.getItem
> -------------------------------
>
>                 Key: JCR-4674
>                 URL: https://issues.apache.org/jira/browse/JCR-4674
>             Project: Jackrabbit Content Repository
>          Issue Type: Bug
>          Components: jackrabbit-core
>    Affects Versions: 2.20.0
>            Reporter: Hannes Weichel
>            Priority: Major
>         Attachments: repository.xml
>
>
> We run a Jackrabbit in a Tomcat (8.5) system with many parallel user ( > 30000 parallel user ). Jackrabbit runs mostly fast and stable. But at a certain point of load the threads are blocking each other. Most threads are blocked at the following position:
> (~28000 threads all blocking): 
>  *org.apache.jackrabbit.core.ItemManager.getItem(ItemManager.java:621)*
> (~2000 threads all blocking):
>  *org.apache.jackrabbit.core.state.DefaultISMLocking.acquireReadLock(DefaultISMLocking.java:114)*
> Even when we block further requests, many threads keep in blocked state. We must hard restart tomcat and throttle user requests to get the system (very slow) back to a working state. 
> What we tried so far to prevent this behavior (with no success):
>  - configured the bundleCacheSize (see attached repository.xml )
>  - configured derbyStoragePageCacheSize
>  - used a JCR-Session Pool
>  - adding <ISMLocking class="org.apache.jackrabbit.core.state.FineGrainedISMLocking"/> in repository.xml 
>  - give the system more Hardware (20 Cores, 128 GB RAM, faster Storage) - but hardware is not the problem.
>  - fine tuned tomcat for more und faster threads
>  
> *here some example StackTraces:*
>  
> http-nio-8080-exec-11367
>  org.apache.jackrabbit.core.ItemManager.getItem(ItemManager.java:621)
>  org.apache.jackrabbit.core.security.authorization.acl.CompiledPermissionsImpl.canRead(CompiledPermissionsImpl.java:254)
>  org.apache.jackrabbit.core.security.DefaultAccessManager.canRead(DefaultAccessManager.java:265)
>  org.apache.jackrabbit.core.ItemManager.canRead(ItemManager.java:437)
>  org.apache.jackrabbit.core.ItemManager.createItemData(ItemManager.java:847)
>  org.apache.jackrabbit.core.ItemManager.getItemData(ItemManager.java:391)
>  org.apache.jackrabbit.core.ItemManager.getItem(ItemManager.java:328)
>  org.apache.jackrabbit.core.ItemManager.getItem(ItemManager.java:621)
>  org.apache.jackrabbit.core.NodeImpl$11.perform(NodeImpl.java:2258)
>  org.apache.jackrabbit.core.NodeImpl$11.perform(NodeImpl.java:2252)
>  org.apache.jackrabbit.core.session.SessionState.perform(SessionState.java:216)
>  org.apache.jackrabbit.core.ItemImpl.perform(ItemImpl.java:91)
>  org.apache.jackrabbit.core.NodeImpl.getProperty(NodeImpl.java:2252)
>  ...
>  
> http-nio-8080-exec-11352
>  org.apache.jackrabbit.core.ItemManager.getItem(ItemManager.java:621)
>  org.apache.jackrabbit.core.security.authorization.acl.CompiledPermissionsImpl.canRead(CompiledPermissionsImpl.java:254)
>  org.apache.jackrabbit.core.security.DefaultAccessManager.canRead(DefaultAccessManager.java:265)
>  org.apache.jackrabbit.core.ItemManager.canRead(ItemManager.java:437)
>  org.apache.jackrabbit.core.ItemManager.createItemData(ItemManager.java:847)
>  org.apache.jackrabbit.core.ItemManager.getItemData(ItemManager.java:391)
>  org.apache.jackrabbit.core.ItemManager.itemExists(ItemManager.java:304)
>  org.apache.jackrabbit.core.ItemManager.itemExists(ItemManager.java:522)
>  org.apache.jackrabbit.core.NodeImpl.hasProperty(NodeImpl.java:2460)
>  ...
> http-nio-8080-exec-11382
>  org.apache.jackrabbit.core.ItemManager.getItem(ItemManager.java:621)
>  org.apache.jackrabbit.core.security.authorization.acl.CompiledPermissionsImpl.canRead(CompiledPermissionsImpl.java:254)
>  org.apache.jackrabbit.core.security.DefaultAccessManager.canRead(DefaultAccessManager.java:265)
>  org.apache.jackrabbit.core.ItemManager.canRead(ItemManager.java:437)
>  org.apache.jackrabbit.core.ItemManager.createItemData(ItemManager.java:847)
>  org.apache.jackrabbit.core.ItemManager.getItemData(ItemManager.java:391)
>  org.apache.jackrabbit.core.ItemManager.getNode(ItemManager.java:668)
>  org.apache.jackrabbit.core.ItemManager.getNode(ItemManager.java:646)
>  org.apache.jackrabbit.core.LazyItemIterator.prefetchNext(LazyItemIterator.java:120)
>  org.apache.jackrabbit.core.LazyItemIterator.next(LazyItemIterator.java:257)
>  org.apache.jackrabbit.core.LazyItemIterator.nextNode(LazyItemIterator.java:166)
>  ...
> http-nio-8080-exec-11357
>  org.apache.jackrabbit.core.state.DefaultISMLocking.acquireReadLock(DefaultISMLocking.java:114)
>  org.apache.jackrabbit.core.state.SharedItemStateManager.acquireReadLock(SharedItemStateManager.java:1893)
>  org.apache.jackrabbit.core.state.SharedItemStateManager.getItemState(SharedItemStateManager.java:268)
>  org.apache.jackrabbit.core.state.LocalItemStateManager.getPropertyState(LocalItemStateManager.java:135)
>  org.apache.jackrabbit.core.state.LocalItemStateManager.getItemState(LocalItemStateManager.java:177)
>  org.apache.jackrabbit.core.state.XAItemStateManager.getItemState(XAItemStateManager.java:260)
>  org.apache.jackrabbit.core.state.SessionItemStateManager.getItemState(SessionItemStateManager.java:161)
>  org.apache.jackrabbit.core.ItemManager.getItemData(ItemManager.java:382)
>  org.apache.jackrabbit.core.ItemManager.itemExists(ItemManager.java:304)
>  org.apache.jackrabbit.core.ItemManager.itemExists(ItemManager.java:522)
>  org.apache.jackrabbit.core.NodeImpl.hasProperty(NodeImpl.java:2460)
>  



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