Andreas Lanz ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) *created* an issue Hibernate Validator ( https://hibernate.atlassian.net/browse/HV?atlOrigin=eyJpIjoiMTdlZTMzZWZkM... ) / Bug ( https://hibernate.atlassian.net/browse/HV-1947?atlOrigin=eyJpIjoiMTdlZTMz... ) HV-1947 ( https://hibernate.atlassian.net/browse/HV-1947?atlOrigin=eyJpIjoiMTdlZTMz... ) JPATraversableResolver is not Thread-Safe ( https://hibernate.atlassian.net/browse/HV-1947?atlOrigin=eyJpIjoiMTdlZTMz... ) Issue Type: Bug Affects Versions: 6.2.5.Final Assignee: Unassigned Created: 02/May/2023 07:23 AM Priority: Major Reporter: Andreas Lanz ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) org.hibernate.validator.internal.engine.resolver.JPATraversableResolver and thus also org.hibernate.validator.internal.engine.ValidatorImpl are not Thread-Safe which according to the contract of javax.validation.TraversableResolver and javax.validation.Validator they must be. In particular, JPATraversableResolver ultimately calls org.hibernate.jpa.internal.util.PersistenceUtilHelper#isLoadedWithReference which uses PersistenceUtilHelper$MetadataCache. This class has a //TODO not really thread-safe and from the code it’s obvious that it isn’t thread-safe as it uses a simple WeakHashMap with no synchronization and there is nothing in the call chain doing any synchronization. Here is a stacktrace that shows the call chain. org.hibernate.jpa.internal.util.PersistenceUtilHelper$MetadataCache.getClassMetadata(PersistenceUtilHelper.java:424) at org.hibernate.jpa.internal.util.PersistenceUtilHelper.isLoadedWithReference(PersistenceUtilHelper.java:216) at org.hibernate.jpa.HibernatePersistenceProvider$1.isLoadedWithReference(HibernatePersistenceProvider.java:186) at javax.persistence.Persistence$PersistenceUtilImpl.isLoaded(Persistence.java:155) at org.hibernate.validator.internal.engine.resolver.JPATraversableResolver.isReachable(JPATraversableResolver.java:52) This is causing us some issues as we’re using org.hibernate.validator.internal.engine.ValidatorImpl in a massive parallel context and from time to time we’re seeing deadlocks in the system with the above stacktrace when starting the system. ( https://hibernate.atlassian.net/browse/HV-1947#add-comment?atlOrigin=eyJp... ) Add Comment ( https://hibernate.atlassian.net/browse/HV-1947#add-comment?atlOrigin=eyJp... ) Get Jira notifications on your phone! Download the Jira Cloud app for Android ( https://play.google.com/store/apps/details?id=com.atlassian.android.jira.... ) or iOS ( https://itunes.apple.com/app/apple-store/id1006972087?pt=696495&ct=Em... ) This message was sent by Atlassian Jira (v1001.0.0-SNAPSHOT#100224- sha1:07bd2b7 )