Guaranteed delivery is a Delivery Mode option within a nested pipeline.

Guaranteed delivery holds the documents in the backing store until the Snap acknowledges that the document has been processed successfully. If there is no acknowledgement from the Snap, the document is replayed so that the Snap can try to process the document again. Retry is controlled by the retry policy that is set on the nested pipeline properties.

Use Case

ServiceNow Query > Join with Data From DB > Write to Salesforce

A pipeline that fetches the data from ServiceNow and merges the data with an in house database and finally writes to Salesforce.

If a user wants to write the documents to an external endpoint like Salesforce, there is a chance that the endpoint may not respond intermittently. In this case, if the write to the external endpoint is attempted again after a few seconds, it may work. The retry mechanism configured in the nested pipeline will help in redelivering the document to the external endpoint after a short duration instead of just marking the document as failure.