Event subscription retries

When implementing a message delivery system there are a few caveats that must be addressed in order to ensure stability, consistency, and good user experience. One of the shortcomings of a message delivery system is ensuring messages reach their destination successfully and knowing what to do when messages fail to arrive.

Some integrations can accept failure of delivery, and then drop the message and move to the next message. In other integrations, failure to deliver a message cannot be ignored. For example, a financial integration might attempt to deliver a message, but instead receives an HTTP status code of 404, which indicates the server could not find the endpoint to which the message was to be delivered. In such cases, a missing message could mean someone not being paid for their time or an organization going over budget on contracted resources.

Adobe Workfront Strategy for Event Subscription Retries

Because customers leverage the Workfront platform as a core piece of their daily knowledge work, the Workfront Event Subscription framework provides a mechanism to ensure that the delivery of each message is attempted to the fullest extent possible.

Event-triggered outbound messages that fail to be delivered to customer endpoints are resent until delivery is successful for up to a period of 48 hours. During this time, retries occur at an incrementally increased frequency until delivery is successful or until 11 attempts have been made.

The formula for these retry attempts is:

((2^attempt) - 1) * 84800ms

The first retry occurs after 1.5 minutes, second at almost 5 minutes, and 11th is at about 48 hours.

Customers need to ensure that any endpoints consuming outbound messages from Workfront Event Subscriptions are set up to return a 200-level response message back to Workfront when delivery is successful.