[hibernate-issues] [Hibernate-JIRA] Commented: (HHH-2631) Leaking PreparedStatement and ResultSet via CollectionLoadContext instances maintained in Map collectionLoadContexts in LoadContexts

Leaking PreparedStatement and ResultSet via CollectionLoadContext instances maintained in Map collectionLoadContexts in LoadContexts ------------------------------------------------------------------------------------------------------------------------------------ Key: HHH-2631 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-2631 Project: Hibernate3 Issue Type: Bug Components: core Affects Versions: 3.2.4 Environment: hibernate 3.2.3 with patch from HHH-2553 Reporter: Douglas A. Herrick Assignee: Steve Ebersole Fix For: 3.2.5, 3.3 Attachments: HHH-2631.patch While diagnosing an apparent resource issue, while running our application for a couple of hours I noticed over time that the number of PreparedStatement and ResultSet instances continued to grow, eventually consuming a fair amount of memory. After digging around a bit, I saw that the entries LoadContext.java inserts into the map named collectionLoadContexts are not removed from the map [method cleanup(ResultSet resultSet) might have removed them, but I never witnessed its invocation, nor did I find any references to it). I pasted below a stack trace that shows the insertion of elements into collectionLoadContexts: Thread [http-9943-Processor2] (Suspended (breakpoint at line 53 in CollectionLoadContext)) CollectionLoadContext.<init>(LoadContexts, ResultSet) line: 53 LoadContexts.getCollectionLoadContext(ResultSet) line: 85 BasicCollectionLoader(Loader).handleEmptyCollections(Serializable[], Object, SessionImplementor) line: 1060 BasicCollectionLoader(Loader).doQuery(SessionImplementor, QueryParameters, boolean) line: 690 BasicCollectionLoader(Loader).doQueryAndInitializeNonLazyCollections(SessionImplementor, QueryParameters, boolean) line: 236 BasicCollectionLoader(Loader).loadCollection(SessionImplementor, Serializable, Type) line: 1994 BasicCollectionLoader(CollectionLoader).initialize(Serializable, SessionImplementor) line: 36 BasicCollectionPersister(AbstractCollectionPersister).initialize(Serializable, SessionImplementor) line: 565 DefaultInitializeCollectionEventListener.onInitializeCollection(InitializeCollectionEvent) line: 60 SessionImpl.initializeCollection(PersistentCollection, boolean) line: 1716 PersistentSet(AbstractPersistentCollection).forceInitialization() line: 454 StatefulPersistenceContext.initializeNonLazyCollections() line: 785 QueryLoader(Loader).doQueryAndInitializeNonLazyCollections(SessionImplementor, QueryParameters, boolean) line: 241 QueryLoader(Loader).doList(SessionImplementor, QueryParameters) line: 2220 QueryLoader(Loader).listIgnoreQueryCache(SessionImplementor, QueryParameters) line: 2104 QueryLoader(Loader).list(SessionImplementor, QueryParameters, Set, Type[]) line: 2099 QueryLoader.list(SessionImplementor, QueryParameters) line: 378 QueryTranslatorImpl.list(SessionImplementor, QueryParameters) line: 338 HQLQueryPlan.performList(QueryParameters, SessionImplementor) line: 172 SessionImpl.list(String, QueryParameters) line: 1121 QueryImpl.list() line: 79 HibQuery.list() line: 60 HibRepository(AbstractRepository).query(IQuery, Class) line: 300 ... While subsequent to this logic, hibernate does close the PreparedStatement and ResultSet instances, since it never removes them from collectionLoadContexts map, those instances are never GCed. After running our application for a couple of days the amount of storage attributed to this potential leak is significant.