Memory leak in wildfly transaction client ----------------------------------------- Key: WFLY-12031 URL: https://issues.jboss.org/browse/WFLY-12031 Project: WildFly Issue Type: Bug Components: Transactions Affects Versions: 15.0.1.Final Environment: wildfly-transaction-client-1.1.3.Final wildfly.15.0.1.Final Window 10 Reporter: Joachim Petrich Assignee: Cheng Fang Priority: Critical After a volume run of our system we recognized millions of entries in the openFilePaths Object of class FileSystemXAResourceRegistry. When enabling traces for org.wildfly.transaction it seems that for adding an entry a xid string is used {code:java} XAResourceRegistryFile(Xid xid) throws SystemException { xaRecoveryPath.toFile().mkdir(); // create dir if non existent final String xidString = SimpleXid.of(xid).toHexString('_'); this.filePath = xaRecoveryPath.resolve(xidString); openFilePaths.add(*xidString*); {code} and for removing the entire file path: {code:java} protected void removeResource(XAResource resource) throws XAException { if (resources.remove(resource)) { if (resources.isEmpty()) { // delete file try { if (fileChannel != null) { fileChannel.close(); } Files.delete(filePath); // deleting using the filepath as key caused a memory leak, // if xid string have been added, therefore build the xid string for removing openFilePaths.remove(*filePath.toString()*); {code} We didn't find any code where this xid are cleaned up. As workaround we additionally extract the xid String from the file path and remove the corresponding entry. {code:java} String xidString = filePath.toString().substring(filePath.toString().indexOf( xaRecoveryPath.toString()) + xaRecoveryPath.toString().length() + 1); openFilePaths.remove(xidString); {code}