Posts tagged "idempotency"

A consumer's database commit, broker acknowledgement, and external calls do not form one automatic transaction. Draw each durable boundary and test every crash gap.

A deduplication TTL must cover every supported path by which an old message can return. Derive the window from retries, replays, outages, and redrives.

Agent retries must reuse one logical action identity and reconcile uncertain effects. An effect ledger makes autonomy bounded, inspectable, and recoverable.

An SFTP folder is not a queue. Reliable imports need a ready-file contract, stable file identity, durable claims, idempotent processing, and reconciliation.

When you sync two systems with webhooks, the copy slowly becomes wrong: some events are lost, some are duplicated, some arrive in the wrong order. Reconciliation is the way to make the two systems agree again. Here is how to design an API for it.