[ https://issues.jboss.org/browse/WFLY-9849?page=com.atlassian.jira.plugin.... ] Scott Marlow commented on WFLY-9849: ------------------------------------ I'm currently looking at wildfly-leak-2.hprof with the [https://www.eclipse.org/mat/] tool. In the Histogram view, I filtered on the name of the leaked class "org.hibernate.internal.SessionFactoryImpl" and see that we have four objects with name=HibernateTestPU: {code} Class Name | Objects | Shallow Heap | Retained Heap ------------------------------------------------------------------------------------------------------ org.hibernate.internal.SessionFactoryImpl$3 | 0 | 0 | org.hibernate.internal.SessionFactoryImpl$2 | 0 | 0 | org.hibernate.internal.SessionFactoryImpl$1IntegratorObserver| 4 | 96 | >= 416 org.hibernate.internal.SessionFactoryImpl$1 | 0 | 0 | org.hibernate.internal.SessionFactoryImpl | 4 | 544 | >= 797,032 ------------------------------------------------------------------------------------------------------ {code} One of the paths to SessionFactoryImpl shows: {code} Class Name | Ref. Objects | Shallow Heap | Ref. Shallow Heap | Retained Heap ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- org.jboss.msc.service.ServiceContainerImpl$ServiceThread @ 0xe0103d28 MSC service thread 1-5 Thread | 1 | 128 | 136 | 4,168 '- container org.jboss.msc.service.ServiceContainerImpl @ 0xe0486e20 | 1 | 104 | 136 | 26,576 '- registry java.util.concurrent.ConcurrentHashMap @ 0xe0487078 | 1 | 64 | 136 | 25,408 '- table java.util.concurrent.ConcurrentHashMap$Node[1024] @ 0xe06a5cb8 | 1 | 4,112 | 136 | 25,328 '- [820] java.util.concurrent.ConcurrentHashMap$Node @ 0xe1059098 | 1 | 32 | 136 | 64 '- next java.util.concurrent.ConcurrentHashMap$Node @ 0xe17b8638 | 1 | 32 | 136 | 32 '- val org.jboss.msc.service.ServiceRegistrationImpl @ 0xe13da8a8 | 1 | 40 | 136 | 104 '- instance org.jboss.msc.service.ServiceControllerImpl @ 0xe194f4c8 | 1 | 120 | 136 | 912 '- serviceValue org.jboss.msc.value.ImmediateValue @ 0xe194f540 | 1 | 16 | 136 | 16 '- value org.jboss.as.jpa.service.PersistenceUnitServiceImpl @ 0xe194f550 | 1 | 80 | 136 | 424 '- entityManagerFactory org.hibernate.jpa.internal.EntityManagerFactoryImpl @ 0xe194f9b8| 1 | 56 | 136 | 5,728 '- sessionFactory org.hibernate.internal.SessionFactoryImpl @ 0xe18b84c0 | 1 | 136 | 136 | 122,728 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- {code} It seems like the org.jboss.as.jpa.service.PersistenceUnitServiceImpl that references the HibernateTestPU didn't getting stopped at undeployment time. Could you please try [enabling TRACE logging for org.jboss.as.jpa|http://docs.wildfly.org/12/Developer_Guide.html#troubles...] and attach the standalone/log/server.log that shows application deployment and undeployment of the HibernateLeakTest jar. I'm looking to see if an error occurred during undeployment that might help us understand what happened. -- This message was sent by Atlassian JIRA (v7.5.0#75005)