Chuck Rolke created QPID-4421:
---------------------------------

             Summary: C++ Broker Issue with reusing link channel Id number too 
soon
                 Key: QPID-4421
                 URL: https://issues.apache.org/jira/browse/QPID-4421
             Project: Qpid
          Issue Type: Bug
          Components: C++ Broker
    Affects Versions: 0.18
            Reporter: Chuck Rolke


Following on to QPID-4392

As you add and remove replicated queues within an HA broker, bridges are opened 
and closed for each queue.  Closing a bridge immediately re-adds the associated 
channel number into an available pool.  As a result, when the old bridge 
(channel X) is closed it sends a "detach" command to the broker and the new 
bridge (assigned the same channel X) sends an "attach" command.  The broker 
will eventually respond with a "detached" command which was meant for the 
original bridge on channel X.  Unfortunately, the new bridge on channel X 
handles this detached command from the broker and flags the bridge as detached. 
 This process can then repeat for several cycles until it break out of the 
detach/attach/detached race.

In addition to the detach/attach/detached race, the immediate re-use of channel 
numbers appears to create other issues like the following:

Nov  2 11:26:40 itcm31 qpidd[12122]: 2012-11-02 11:26:40 [Protocol] error 
Execution exception: invalid-argument: 
anonymous.qpid.bridge_session_qpid.replicator-Queue1.b64c23e6-cb01-4297-8935-c12b40
804ae2_84209514-2e58-4fb9-8d37-7c2440f5f144: confirmed < (2+0) but only sent < 
(0+0) (qpid/SessionState.cpp:154)

This issue may be worked around by assigning channel Id numbers from the pool 
in increasing serial order and not immediately reusing a deallocated Id. 
Although this does not fix the problem of the race condition it will provide 
relief.


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