[AMQ-3999] Unsubscribing durable subs can be blocked on calls to determine store size, contending with active subs

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 5.6.0
• Fix Version/s: 5.7.0
• Component/s: Broker
• Assignee: Gary Tully
• Reporter: Gary Tully
• Created: 28/Aug/12 11:36
• Updated: 28/Aug/12 12:08
• Resolved: 28/Aug/12 12:08

Description

Here is the stack trace showing the thread that is making the call to the getMessageCount when a sub is unsubscribing. This causes unnecessary contention with message addition and can result is pauses. Is it really necessary?

ActiveMQ Transport: tcp:///127.0.0.1:54115
sun.misc.Unsafe.park at line #-2
java.util.concurrent.locks.LockSupport.park at line #186
java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt at line #834
java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued at line #867
java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire at line #1197
java.util.concurrent.locks.ReentrantReadWriteLock$WriteLock.lock at line #945
org.apache.activemq.store.kahadb.KahaDBStore$KahaDBTopicMessageStore.getMessageCount at line #782
org.apache.activemq.store.ProxyTopicMessageStore.getMessageCount at line #116
org.apache.activemq.broker.region.cursors.TopicStorePrefetch.getStoreSize at line #83
org.apache.activemq.broker.region.cursors.AbstractStoreCursor.resetSize at line #66
org.apache.activemq.broker.region.cursors.AbstractStoreCursor.gc at line #246
org.apache.activemq.broker.region.cursors.StoreDurableSubscriberCursor.stop at line #98
org.apache.activemq.broker.region.DurableTopicSubscription.deactivate at line #171
org.apache.activemq.broker.region.TopicRegion.removeConsumer at line #164
org.apache.activemq.broker.region.RegionBroker.removeConsumer at line #473
org.apache.activemq.broker.jmx.ManagedRegionBroker.removeConsumer at line #266
org.apache.activemq.broker.BrokerFilter.removeConsumer at line #117
org.apache.activemq.broker.BrokerFilter.removeConsumer at line #117
org.apache.activemq.broker.MutableBrokerFilter.removeConsumer at line #123
org.apache.activemq.broker.TransportConnection.processRemoveConsumer at line #580
org.apache.activemq.broker.TransportConnection.processRemoveSession at line #617
org.apache.activemq.command.RemoveInfo.visit at line #74
org.apache.activemq.broker.TransportConnection.service at line #291
org.apache.activemq.broker.TransportConnection$1.onCommand at line #149
org.apache.activemq.transport.MutexTransport.onCommand at line #50
org.apache.activemq.transport.WireFormatNegotiator.onCommand at line #113
org.apache.activemq.transport.AbstractInactivityMonitor.onCommand at line #229
org.apache.activemq.transport.TransportSupport.doConsume at line #83
org.apache.activemq.transport.tcp.TcpTransport.doRun at line #215
org.apache.activemq.transport.tcp.TcpTransport.run at line #197
java.lang.Thread.run at line #722