Adding Echo Suppression to Update Trigger Services
The update trigger service receives the canonical document that describes a data change. The echo suppression logic in an update service determines whether a latch is open or closed before it attempts to use the information in the canonical document to update a resource with the data change.
If the latch is open, the data change has not yet been made to the resource. In this case, the update service builds and sends the native document that informs the target resource of the data change. The update service closes the latch to prevent a circular update.
If the latch is closed, the resource was the source of the data change and has already made the data change. In this case, the update service does not need build and send the native document. The update service should simply re‑open the latch and terminate processing.
The following diagram highlights the part of data synchronization that this section addresses.
