[hibernate-issues] [Hibernate-JIRA] Commented: (HHH-6414) CPU spinning, stuck on getResultList()

[Guenther Demetz (JIRA)]

    [ https://hibernate.onjira.com/browse/HHH-6414?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=45704#comment-45704 ] 

Guenther Demetz commented on HHH-6414:
--------------------------------------

Hi Mr. Ogier,
hi Mr Lukasiuk,

if your CPU's are on 100% and your threads are very often executing in

java.util.HashMap.put(HashMap.java:374)
org.hibernate.engine.StatefulPersistenceContext.addCollection(StatefulPersistenceContext.java:...)

then I see only 2 plausible conclusions:

1. You are loading very big collections.
   To check this, please try to log the concerning Query statement, and find out how many records are returned.
   Needless to say that loading very large collections can become CPU instensive.
   In such case the relations should be modelled in another way, or alternatively you can use the EXTRA_LAZY feature.
   So please tell us how big (concrete size of loaded collection) your collections are.

2. Your are running into a concurrency problem like reported in JGRP-525.
   Such concurrency can only happen, if you are working with concurrent 2 threads on the same hiberante session.
   That's not allowed in Hiberante.


> CPU spinning, stuck on getResultList()
> --------------------------------------
>
>                 Key: HHH-6414
>                 URL: https://hibernate.onjira.com/browse/HHH-6414
>             Project: Hibernate ORM
>          Issue Type: Bug
>          Components: core
>    Affects Versions: 3.3.1
>         Environment: Hibernate Annotations 3.4.0.GA, Hibernate 3.3.1.GA, Hibernate Commons Annotations 3.1.0.GA, Hibernate EntityManager 3.4.0.GA, Seam 2.2.1.Final, JBoss 5.1.0.GA, Windows Server 2008 64bits, Microsoft SQL Server 10.00.4000, JDBC driver: Microsoft SQL Server 2005 JDBC Driver, version: 1.2.2828.100
>            Reporter: Anthony Ogier
>
> I've got a web application which is well tested (JMeter etc), and suddenly today, 2 of JBoss threads were stuck on a getResultList(), using 100% of the CPU.
> Here is the stack for each of the threads :
> {noformat}
> Thread: http-0.0.0.0-8080-2 : priority:5, demon:true, threadId:156, threadState:RUNNABLE
> java.util.HashMap.put(HashMap.java:374)
> org.hibernate.engine.StatefulPersistenceContext.addCollection(StatefulPersistenceContext.java:787)
> org.hibernate.engine.StatefulPersistenceContext.addUninitializedCollection(StatefulPersistenceContext.java:756)
> org.hibernate.type.CollectionType.getCollection(CollectionType.java:642)
> org.hibernate.type.CollectionType.resolveKey(CollectionType.java:430)
> org.hibernate.type.CollectionType.resolve(CollectionType.java:424)
> org.hibernate.engine.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:139)
> org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:877)
> org.hibernate.loader.Loader.doQuery(Loader.java:752)
> org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)
> org.hibernate.loader.Loader.doList(Loader.java:2228)
> org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2125)
> org.hibernate.loader.Loader.list(Loader.java:2120)
> org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:401)
> org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:361)
> org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:196)
> org.hibernate.impl.SessionImpl.list(SessionImpl.java:1148)
> org.hibernate.impl.QueryImpl.list(QueryImpl.java:102)
> org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:67)
> {noformat}
> I've seen some similar problems here [JGRP-525|https://issues.jboss.org/browse/JGRP-525] and here [JBMESSAGING-1676|https://issues.jboss.org/browse/JBMESSAGING-1676] and they are talking about concurrency ...

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