Why are messages moved to the default AQ exception queue upon propagation failures for an outbound propagation job?
The MAX_RETRIES parameter of AQ queues controls when AQ moves messages to an AQ exception queue for a failed dequeue attempt. The default value is NULL, which resolves to the value 5 in Oracle 9i. If the parameter value is too small, messages in the queues can be moved into AQ exception queues if the MGW agent keeps running into failures when processing MGW subscribers. The AQ messages moved to AQ exception queues cause unrecoverable failures on the associated MGW subscribers. The MAX_RETRIES parameter for AQ queues that are used as a propagation source should be set to at least 16, and preferably a much larger value.
