Locks, workers and queues
The blue banner, the "already in progress" message, and how to stop a long job.
A lock per order
The connector prevents the same order from being processed twice at once. If two events for one order arrive back to back, the first is processed and the second gets a message meaning "a run is already in progress, try again later".
That message is not an error
Seeing it in the event log is normal on a busy store and does not mean anything was lost: the first event did the work.
Background workers
Long jobs — loading every product, auto-mapping, Retry Fix All, or pulling orders — run in the background and show a blue banner describing what is being processed.
Cancelling a job
Next to the blue banner is a Cancel the process link. Use it if you started a job on a wider scope than you meant to. Cancelling stops what remains; it does not undo what has already run.
One job at a time
Do not start two long jobs together. Wait for the blue banner to disappear before starting the second, or they contend over the same data.