[ https://issues.redhat.com/browse/WFLY-13933?page=com.atlassian.jira.plugi... ] Bartosz Baranowski commented on WFLY-13933: ------------------------------------------- It looks like few undertow related classes violate contracts. [https://github.com/undertow-io/undertow/blob/master/core/src/main/java/io...] Implements Closeable. It has single method, which has following contract: ??Closes this stream and releases any system resources associated with it. If the stream is already closed then invoking this method has no effect.?? ??As noted in [{{AutoCloseable.close()}}|https://docs.oracle.com/javase/8/docs/api/j..., cases where the close may fail require careful attention. It is strongly advised to relinquish the underlying resources and to internally _mark_ the {{Closeable}} as closed, prior to throwing the {{IOException}}.?? As is, close method in DefaultAccessLogReceiver just flip a boolean flag. Actually resource freeing actions are performed in another thread( XnioWorker). Second violation is in [https://github.com/wildfly/wildfly/blob/master/undertow/src/main/java... In Service([https://github.com/jboss-msc/jboss-msc/blob/1.4/src/main/java/or... on stop there: ??Stop the service. Do not return until the service has been fully stopped, unless an asynchronous service stop is performed.?? In both cases current behavior violate contract. In case of DefaultAccessLogReceiver - stream is still open after close() method returns. IT is possible for stream to remain open, if thread, in which it is supposed to be closed is terminated prior full write or even execution due to changes in -WFCORE-1632.- As to AccessLogService - all underlying resources are not stopped when method returns from stop(). As is,  IoUtils.safeClose((DefaultAccessLogReceiver) logReceiver); only flips flag in log receiver. Not only that, it does it only if DefaultLogReceiver is being used(not sure if its possible to configure something else, but it might be, judging from this check).     -- This message was sent by Atlassian Jira (v7.13.8#713008)