Session preservator saves user session. Task management associates the task with returned UUID corresponding to the preserved session.

Session preservator acquires a persistent token (or other equivalents) to preserve the identity.

Workflow is journalled in

VPX_JOURNAL

and associated tables. The first action in workflow is

RedoableAction

, which is responsible for restarting the operation during recovery. Transaction manager loads workflow journals from database. For each pending continuous operation, it flags corresponding managed entities in recovery so that the entities do not participate in conflicting operations while recovery is in progress.

Restart begins. Recovery long-running operation revives persisted session. The session becomes the current user session for later privilege checks. Recovery cleans up previous operation that was interrupted, publishing any cleanup issues encountered in events or tasks.

RedoableAction

checks if the operation should be restarted. If ye,s it will continue to the rest of recovery, otherwise it sets the task error status. Conditions when an operation should be restarted are an implementation detail, for example, it might not restart if the maximum number of retries was exceeded.

If the interruption occurs right before task status is updated, the situation is handled by performing the workflow commit and task update in a single transaction.