Core management server shutting down a thread pool early, resulting in RejectedExecutionException ------------------------------------------------------------------------------------------------- Key: WFCORE-756 URL: https://issues.jboss.org/browse/WFCORE-756 Project: WildFly Core Issue Type: Bug Components: Domain Management Reporter: Ladislav Thon Assignee: Brian Stansberry Priority: Critical Fix For: 2.0.0.CR1 In one of our tests, we've seen this exception during server shutdown: {code} 2015-06-05 10:34:44,387 ERROR [org.xnio.listener] (XNIO-1 I/O-2) XNIO001007: A channel event listener threw an exception: java.util.concurrent.RejectedExecutionException: Task org.jboss.remoting3.remote.RemoteReadListener$1$1@5e7925db rejected from org.xnio.XnioWorker$TaskPool@3d00aa37[Shutting down, pool size = 7, active threads = 0, queued tasks = 0, completed tasks = 52] at java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:2047) at java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:823) at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1369) at org.xnio.XnioWorker.execute(XnioWorker.java:741) at org.jboss.remoting3.remote.RemoteReadListener$1.handleEvent(RemoteReadListener.java:54) ... {code} This is a very basic test that only starts the server and then shuts it down using {{:shutdown}}. After looking into this for a while, I believe that this is caused by the core management server ({{UndertowHttpManagementService}}) shutting down an XNIO worker (= thread pool) while the {{:shutdown}} management operation is still running (or, in fact, finishing, trying to close the network connection). I have a Byteman-based reproducer that inserts artifical pauses to certain well-defined places. I'm not sure if this has some connection to the graceful shutdown system, but I believe that even if it does, something like this shouldn't happen. Steps to reproduce: # {{./bin/standalone.sh -c standalone-full-ha.xml}} and wait until it starts completely # {{jps -v | grep "\-D\\[Standalone\\]"}} to figure out the PID of the newly started server # {{bminstall.sh -b -Dorg.jboss.byteman.transform.all $PID}} # {{bmsubmit.sh reproducer.btm}}, where {{reproducer.btm}} is a Byteman script reproduced below # {{./bin/jboss-cli.sh -c}} # {{:read-resource}} repeat few times # {{:shutdown(timeout=1)}} (or plain {{:shutdown}}) The Byteman script: {code} RULE XnioWorker.TaskPool/ThreadPoolExecutor shutdown CLASS java.util.concurrent.ThreadPoolExecutor METHOD shutdown() AFTER INVOKE advanceRunState IF TRUE DO Thread.sleep(10000) ENDRULE RULE Remoting onClose handler CLASS org.jboss.remoting3.remote.RemoteReadListener$1 METHOD handleEvent(java.nio.channels.Channel) AT ENTRY IF TRUE DO Thread.sleep(5000) ENDRULE {code}