[ARTEMIS-2206] The MQTT consumer reconnection caused the queue to not be cleared and throw a NullPointerException exception

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.6.3
• Fix Version/s: 2.7.0
• Component/s: MQTT

Environment

1. Use 10,000 (9 thousand senders, 1 thousand consumers) MQTT connection on one server to test Artemis, set the 'cleanSession' property to true；
2. MQTT client: paho 1.2.0;
3. Server: CPU Cores:32, Mem:64G, SSD:250G, HDD:1T

• Assignee: Unassigned
• Reporter: Shiping Liang
• Created: 18/Dec/18 10:31
• Updated: 14/Mar/19 18:28
• Resolved: 14/Mar/19 18:28

Description

Issue 1
Artemis broker has the following exception log:
[Thread-0 (ActiveMQ-remoting-threads-ActiveMQServerImpl::serverUUID=fb358579-feb3-11e8-bc7c-141877a7fd13-1409545055)] 17:27:59,035 WARN [org.apache.activemq.artemis.utils.actors.OrderedExecutor] null: java.lang.NullPointerException at org.apache.activemq.artemis.core.protocol.mqtt.MQTTProtocolManager.isClientConnected(MQTTProtocolManager.java:182) [:] at org.apache.activemq.artemis.core.protocol.mqtt.MQTTConnectionManager.disconnect(MQTTConnectionManager.java:150) [:] at org.apache.activemq.artemis.core.protocol.mqtt.MQTTFailureListener.connectionFailed(MQTTFailureListener.java:37) [:] at org.apache.activemq.artemis.core.protocol.mqtt.MQTTConnection.fail(MQTTConnection.java:147) [:] at org.apache.activemq.artemis.core.remoting.server.impl.RemotingServiceImpl.issueFailure(RemotingServiceImpl.java:561) [:] at org.apache.activemq.artemis.core.remoting.server.impl.RemotingServiceImpl.connectionDestroyed(RemotingServiceImpl.java:542) [:] at org.apache.activemq.artemis.core.remoting.impl.netty.NettyAcceptor$Listener.connectionDestroyed(NettyAcceptor.java:858) [:] at org.apache.activemq.artemis.core.remoting.impl.netty.ActiveMQChannelHandler.lambda$channelInactive$0(ActiveMQChannelHandler.java:83) [:] at org.apache.activemq.artemis.utils.actors.OrderedExecutor.doTask(OrderedExecutor.java:42) [:] at org.apache.activemq.artemis.utils.actors.OrderedExecutor.doTask(OrderedExecutor.java:31) [:] at org.apache.activemq.artemis.utils.actors.ProcessorBase.executePendingTasks(ProcessorBase.java:66) [:] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [rt.jar:1.8.0_101] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [rt.jar:1.8.0_101] at org.apache.activemq.artemis.utils.ActiveMQThreadFactory$1.run(ActiveMQThreadFactory.java:118) [:]

Issue 2
After closing all client connections, 64 queues were not cleaned up。

Issue Links

• links to: GitHub Pull Request #2466
• links to: GitHub Pull Request #2466