final SimpleFuture<Boolean> known = new SimpleFutureImpl<>();

      // retry on the append thread. maybe the appender thread is not keeping up.
      appendExecutor.execute(new Runnable() {
         @Override
         public void run() {
            journalLock.readLock().lock();
            try {

               known.set(records.containsKey(id)
                  || pendingRecords.contains(id)
                  || (compactor != null && compactor.containsRecord(id)));
            } finally {
               journalLock.readLock().unlock();
            }
         }
      });

      if (!known.get()) {
          ...
      }

"Thread-16 (ActiveMQ-server-org.apache.activemq.artemis.core.server.impl.ActiveMQServerImpl$6@423fe5c3)" #1078 prio=5 os_prio=64 tid=0x000000011c34a000 nid=0x4eb waiting on condition [0xfffffffabe9ad000]
   java.lang.Thread.State: WAITING (parking)
        at sun.misc.Unsafe.park(Native Method)
        - parking to wait for  <0xfffffffbe73c29e8> (a java.util.concurrent.CountDownLatch$Sync)
        at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
        at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
        at java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:997)
        at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1304)
        at java.util.concurrent.CountDownLatch.await(CountDownLatch.java:231)
        at org.apache.activemq.artemis.utils.SimpleFutureImpl.get(SimpleFutureImpl.java:62)
        at org.apache.activemq.artemis.core.journal.impl.JournalImpl.checkKnownRecordID(JournalImpl.java:1080)
        at org.apache.activemq.artemis.core.journal.impl.JournalImpl.appendDeleteRecord(JournalImpl.java:950)
        at org.apache.activemq.artemis.core.persistence.impl.journal.AbstractJournalStorageManager.confirmPendingLargeMessage(AbstractJournalStorageManager.java:361)
        at org.apache.activemq.artemis.core.postoffice.impl.PostOfficeImpl.confirmLargeMessageSend(PostOfficeImpl.java:1390)
        - locked <0xfffffffbe73aa1b0> (a org.apache.activemq.artemis.core.persistence.impl.journal.LargeServerMessageImpl)
        at org.apache.activemq.artemis.core.postoffice.impl.PostOfficeImpl.processRoute(PostOfficeImpl.java:1336)
        at org.apache.activemq.artemis.core.postoffice.impl.PostOfficeImpl.route(PostOfficeImpl.java:980)
        at org.apache.activemq.artemis.core.postoffice.impl.PostOfficeImpl.route(PostOfficeImpl.java:871)
        at org.apache.activemq.artemis.core.server.impl.ServerSessionImpl.doSend(ServerSessionImpl.java:2045)
        - locked <0xfffffffb19447fb8> (a org.apache.activemq.artemis.core.server.impl.ServerSessionImpl)
        at org.apache.activemq.artemis.core.server.impl.ServerSessionImpl.doSend(ServerSessionImpl.java:1989)
        - locked <0xfffffffb19447fb8> (a org.apache.activemq.artemis.core.server.impl.ServerSessionImpl)
        at org.apache.activemq.artemis.core.protocol.core.ServerSessionPacketHandler.sendContinuations(ServerSessionPacketHandler.java:1034)
        - locked <0xfffffffb1962b900> (a java.lang.Object)
        at org.apache.activemq.artemis.core.protocol.core.ServerSessionPacketHandler.slowPacketHandler(ServerSessionPacketHandler.java:312)
        at org.apache.activemq.artemis.core.protocol.core.ServerSessionPacketHandler.onMessagePacket(ServerSessionPacketHandler.java:285)
        at org.apache.activemq.artemis.core.protocol.core.ServerSessionPacketHandler$$Lambda$651/2097400985.onMessage(Unknown Source)
        at org.apache.activemq.artemis.utils.actors.Actor.doTask(Actor.java:33)
        at org.apache.activemq.artemis.utils.actors.ProcessorBase.executePendingTasks(ProcessorBase.java:66)
        at org.apache.activemq.artemis.utils.actors.ProcessorBase$$Lambda$413/494003142.run(Unknown Source)
        at org.apache.activemq.artemis.utils.actors.OrderedExecutor.doTask(OrderedExecutor.java:42)
        at org.apache.activemq.artemis.utils.actors.OrderedExecutor.doTask(OrderedExecutor.java:31)
        at org.apache.activemq.artemis.utils.actors.ProcessorBase.executePendingTasks(ProcessorBase.java:66)
        at org.apache.activemq.artemis.utils.actors.ProcessorBase$$Lambda$413/494003142.run(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java)
        at org.apache.activemq.artemis.utils.ActiveMQThreadFactory$1.run(ActiveMQThreadFactory.java:118)

   Locked ownable synchronizers:
        - <0xfffffffba1800ca0> (a java.util.concurrent.ThreadPoolExecutor$Worker)

"Thread-82 (ActiveMQ-IO-server-org.apache.activemq.artemis.core.server.impl.ActiveMQServerImpl$7@3bde9e44)" #2130 prio=5 os_prio=64 tid=0x000000017b6df800 nid=0x907 waiting for monitor entry [0xffffffff045de000]
   java.lang.Thread.State: BLOCKED (on object monitor)
        at org.apache.activemq.artemis.core.persistence.impl.journal.LargeServerMessageImpl.getEncodeSize(LargeServerMessageImpl.java:178)
        - waiting to lock <0xfffffffbe73aa1b0> (a org.apache.activemq.artemis.core.persistence.impl.journal.LargeServerMessageImpl)
        at org.apache.activemq.artemis.core.persistence.impl.journal.codec.LargeMessagePersister.getEncodeSize(LargeMessagePersister.java:59)
        at org.apache.activemq.artemis.core.persistence.impl.journal.codec.LargeMessagePersister.getEncodeSize(LargeMessagePersister.java:25)
        at org.apache.activemq.artemis.core.journal.impl.dataformat.JournalAddRecord.getEncodeSize(JournalAddRecord.java:79)
        at org.apache.activemq.artemis.core.journal.impl.JournalImpl.appendRecord(JournalImpl.java:2792)
        at org.apache.activemq.artemis.core.journal.impl.JournalImpl.access$100(JournalImpl.java:91)
        at org.apache.activemq.artemis.core.journal.impl.JournalImpl$1.run(JournalImpl.java:850)