Details
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Bug
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Status: Closed
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Major
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Resolution: Duplicate
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5.0.0
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None
Description
This is a reproducible case of a DEAD Consumer that never gets cleaned up.
I am using telnet to manually test STOMP message consumption.
First I put a message into the queue
I then connect and subscribe to that queue and get the message:
CONNECT
login: test
passcode: test
^@
CONNECTED
session:ID:jacob-64807-1188509209664-4:3
SUBSCRIBE
destination: /queue/Prescriptions
ack: client
^@
This works and I receive the queued messages.
They remain in the Q because I am not send ACK
If I use the DISCONNECT command. I am properly disconnected and I can repeat this process to get the same message again. Good.
If I disconnect by killing the telnet process I see the following stack trace in MQ. AND I can still repeat the same process of re-retrieving the un-acknowledged messages:
DEBUG Transport - Transport failed: java.io.EOFException
java.io.EOFException
at java.io.DataInputStream.readByte(DataInputStream.java:243)
at org.apache.activemq.transport.stomp.StompWireFormat.readLine(StompWireFormat.java:186)
at org.apache.activemq.transport.stomp.StompWireFormat.unmarshal(StompWireFormat.java:94)
at org.apache.activemq.transport.tcp.TcpTransport.readCommand(TcpTransport.java:196)
at org.apache.activemq.transport.tcp.TcpTransport.doRun(TcpTransport.java:188)
at org.apache.activemq.transport.tcp.TcpTransport.run(TcpTransport.java:176)
at java.lang.Thread.run(Thread.java:613)
DEBUG TransportConnection - Stopping connection: /XXXXXXXXXXXXXX:4880
DEBUG TcpTransport - Stopping transport tcp:///XXXXXXXXXXXXXX:4880
DEBUG TransportConnection - Stopped connection: /XXXXXXXXXXXXXX:4880
DEBUG TransportConnection - Cleaning up connection resources: /XXXXXXXXXXXXXX:4880
DEBUG AMQPersistenceAdapter - Checkpoint started.
DEBUG AMQPersistenceAdapter - Checkpoint done.
HOWEVER,
If I disconnect by repeatedly typing Control-C to close the telnet program I see the following stack trace:
DEBUG Transport - Transport failed: org.apache.activemq.transport.stomp.ProtocolException: Unable to parser header line [????????????]
org.apache.activemq.transport.stomp.ProtocolException: Unable to parser header line [????????????]
at org.apache.activemq.transport.stomp.StompWireFormat.unmarshal(StompWireFormat.java:121)
at org.apache.activemq.transport.tcp.TcpTransport.readCommand(TcpTransport.java:196)
at org.apache.activemq.transport.tcp.TcpTransport.doRun(TcpTransport.java:188)
at org.apache.activemq.transport.tcp.TcpTransport.run(TcpTransport.java:176)
at java.lang.Thread.run(Thread.java:613)
DEBUG TransportConnection - Stopping connection: /XXXXXXXXXXXXXX:64820
DEBUG TcpTransport - Stopping transport tcp:///XXXXXXXXXXXXXX:64820
DEBUG AMQPersistenceAdapter - Checkpoint started.
DEBUG AMQPersistenceAdapter - Checkpoint done.
AND, I am no longer able to retrieve the queued up messages. Looking at the admin console I see Number Of Consumers = 1, leading me to believe that ActiveMQ didn't properly handle the disconnection. In the other 2 cases (DISCONNECT and kill) the "Number Of Consumers" drops to zero on connection termination.
I believe the correct behavior should be to properly handle and clean-up the connection on bad data. Or perhaps periodically check each of the supposed "Consumers" to make sure that they are still alive. This is clearly a reproducible case of a DEAD Consumer that never gets cleaned up.
Comparing the DEBUG output the follows the 2 stack traces, it is clear in the second case that ActiveMQ fails to clean up the connections resources for the unexpectedly disconnected consumer.