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https://issues.apache.org/jira/browse/QPID-6996?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15101960#comment-15101960
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ASF subversion and git services commented on QPID-6996:
-------------------------------------------------------

Commit 1724844 from [email protected] in branch 'java/trunk'
[ https://svn.apache.org/r1724844 ]

QPID-6996: Set property 'updateAttributeDespiteUnchangedValue' on role 
attribute in BDB HA RemoteReplicationNode and add system tests

> Can't make a node master twice (during a single Broker lifetime)
> ----------------------------------------------------------------
>
>                 Key: QPID-6996
>                 URL: https://issues.apache.org/jira/browse/QPID-6996
>             Project: Qpid
>          Issue Type: Bug
>          Components: Java Broker
>    Affects Versions: 0.30, 0.32, qpid-java-6.0
>            Reporter: Keith Wall
>            Priority: Minor
>         Attachments: roleChangePatch.diff, roleChangePatch2.diff
>
>
> The Java Broker's BDB HA implementation permits the mastership to be 
> transferred around the group.  To initiate this change, a user mutates the 
> model attribute "role" on object {{BDBHAVHN}} or {{BDBHARRN}} to have the 
> value {{MASTER}} through a management interface.
> If I make this change once, the change is effective.  If later the mastership 
> moves again (as a result of a failure and subsequent election or a transfer 
> master elsewhere in the group), the attempt to move the mastership back to 
> this node is ignored (defect).
> The issue is that ACO#changeAttributes blocks the subsequent change because 
> it does not know that attribute's value is anything other than {{MASTER}}.  
> This is because BDBHAVHN#setRole (happens asynchronously as the mastership 
> changes) updates only the CO view of the attribute (#_role), leaving 
> ACO#_attributes.get(ROLE) with a stale value {{MASTER}}.  The Broker 
> containing the node needs to be bounce to correct the state problem.
> The main use-case for transfer master is to restore the master to its 
> business as usual position following a device failure.  This use-case is not 
> affected by this defect.



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