WS-ReliableMessaging sequence reallocation
In some situations, the WS-ReliableMessaging implementation can recover from a sequence-related fault, so the application can continue without having to process the fault itself. The application must still process the fault if the recovery fails.
When a server receives a request on a reliable messaging sequence that is no longer available for processing messages, a SOAP fault is produced. If the fault contains one of the following fault codes, and the message exchange pattern is asynchronous or synchronous one-way, the runtime environment creates a new sequence to the same endpoint and resends any messages that were due for delivery on the original sequence:
- wsrm:SequenceTerminated
- wsrm:MessageNumberRollover
- wsrm:UnknownSequence
These fault codes are contained in a wsrm:FaultCode element, within a wsrm:SequenceFault element in the SOAP header.
Any future messages to the target endpoint are also sent on the new sequence.
If the creation of the new sequence fails, the original fault is returned to the client. The client application must detect the fault and create a new sequence, using the WS-ReliableMessaging system programming interfaces (SPIs), to resend the message.
If the application uses asynchronous messaging, responses from the provider to the client might also be reallocated in this way. Sequence reallocation does not occur when the message exchange pattern is synchronous two-way.
Both the original sequence and the new sequence are visible in the administrative console panels. Do not delete the original sequence; it is automatically deleted after 12 hours. If we delete the original sequence while the new sequence is in use, messages can no longer be sent on the new sequence.
Related:
WS-ReliableMessaging sequences Controlling WS-ReliableMessaging sequences programmatically Inbound sequence collection Outbound sequence collection