Execution states

The state transitions of an execution can be represented in a diagram:

When an execution is first scheduled, it starts in the Queued state (unless caching is enabled and there is a cache hit, in which case it transitions straight to Cached). From the Queued state it will transition to Assigned once it is due, and a suitable agent is available to run it. At that point the agent will generally execute it until it succeeds (Succeeded) or raises an exception (Failed). Executions may become Cancelled either before or after they've been assigned. They may also become Deferred if another execution superseeds it before it's assigned. If contact is lost with an agent for more than the timeout period, the task that are running will be marked as Abandoned (we don't know whether it completed successfully).

If a step is automatically retried or manually re-run, a new execution will be started. An execution will only be automatically retried from the Failed or Abandoned states.