backout/error queue capabilities of broker

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1

What happens to the publishable document after it is picked up by its trigger and corresponding processing service associated with the trigger fails? Does the publishable document vanish totally?

Is there a way to retain the publishable document in the event of failure in the same queue(rollback) or in a backout queue? Does the broker has any inbuilt functionality? This will help me to automate error handling of transient failures.

If the associated processing service fails, can the broker automatically put the publishable document to a backout/error queue? What does it take to accomplish this task?

Regards,
Srinivas

2

What happens to the published document depends on how the trigger service fails. You can force a rollback by calling throwExceptionForRetry. This causes IS to “nack” the document so that it remains on the Broker for a retry, perhaps by another IS instance if there are multiple IS instances connected to the queue.

There is no notion of a backout or error queue.

3

Rob,

Thanks for the response. In this scenario the trigger service is a flow service and will throw a com.wm.lang.flow.FlowException.

Also what did you mean when you said the following:

“This causes IS to “nack” the document so that it remains on the Broker for a retry”

I did not understand the word “nack”

Thank you,
Srinivas

4

nack = negative acknowledgement. Indicates to the Broker that the document should not be removed from the queue and should be reprocessed.

5

Srinivas,

In regards to your comment:

What you can do is have a try-catch block in your Flow service that catches all exceptions and determines if the error is “retriable.” If it is, then invoke pub.flow:throwExceptionForRetry (outside the catch block.)

  • Percio