Hi, I'd like to implement xmlBlaster in an HA setup, with two xmlBlaster instances on two separate nodes acting in a active/standby approach. The two nodes would be implemented as a single subsystem, and a vitrual IP address is assigned to the subsystem for subscriber and publisher clients to access it. The subsystem process determines which xmlBlaster instance to use.
My objective of using xmlBlaster is to use it as a messaging infrastructure between several other heterogeneous subsystems in our application framework. And the existing subsystems are also deployed on several nodes for HA. I'm kind of new to xmlBlaster, and my understanding is that automatic switchover of a slave node to master and the mirroring of master nodes is not supported yet. So my implementation would be something like this: 1) By default, all subscribe and publish sessions would be sent to the active node. All messages are volatile. Connections will register a ConnectionStateListener for fail safe handling. Standby node is idle during this time. 2) If standby node goes down during this time while the active node is still up, no problem. 3) If active node goes down, all existing sessions should be resestablished at the standby node. This will be known when a notification comes to the ConnectionStateListener. The standby node now becomes the active node, and when the previously-active node comes up, it becomes the standby node. Since all sessions at any point of time will only be directed towards one node, and since messages are volatile (i.e. no messages in the queue), I don't think that we need to have the two nodes as master & slave, we just have to ensure that existing client connections are reestablished on the second node. But I could be missing some major drawbacks here on this approach, and any insights or suggestions would be extremely helpful! Thanks in advance, Saju
