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#2253 Problem with Reliable Indication support in the Listener
closed-fixed
5
2011-09-15
2011-08-12
No
Currently the Reliable Indication support assumes that it is listening to a single indication server. IBM Director actually listens to many, hundreds to thousands of individual cim endpoints. This seems like an unrealistic limitation and that the Listener should be able to handle multiple indication servers each with their unique Listener Destination.
The current ReliableIndicationHandler in Java CIM Client assumes a 1:1 relationship between WBEMListener and WBEM indication server. This is not the case in Director, where indications from multiple servers are sent to a single WBEMListener and, in fact, indications from multiple subscriptions on a single server are sent to a single WBEMListener.
The attached patch will enhance the Java CIM Client by creating a ReliableIndicationHandler instance for each unique serverIP/destinationURL pair. This will enable a single WBEMListener to handle indications from multiple servers and/or one server with multiple destination URLs.
THERE IS A LIMITATION TO THIS (and hence DSP1054 v1.2): there is no way for the Client/listener to differentiate between a context switch and two different contexts if the user uses two different CIM_ListenerDestination instances with the same "Destination" property on the same server. This is because the only information available with an incoming indication is the serverIP, destinationURL and indication itself. If the first two are the same, the Client is forced to assume that the SequenceContext will be the same and, if two LD instances are used, they are not.
To avoid this limitation, do not use mutliple CIM_ListenerDestination instances with the same "Destination" property. This is not good programming practice (and frowned upon by CIMOM developers) and will cripple reliable indication support in the Client.
Patch sent for community review. During a 2 week period any
exploiter may comment on the patch, request changes or turn it
down completely (with good reason). For the time being the patch is part of the "Experimental" branch in CVS.
Patch against HEAD
The community review has completed and we received no substantial criticism. Therefore the patch has been approved and merged into the "HEAD" branch. The next release will pick it up.
The patch was picked up by release 2.1.10 and will therefore be closed.