Complete book · 6A. Real-Time and Long-Running Work

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Complete handbook · Section 15 of 31

6A. Real-Time and Long-Running Work

Do not move work behind a queue only because asynchronous architecture sounds scalable. Keep short work synchronous when it meets the request SLA and simpler failure handling is valuable. For genuinely long work, acknowledge quickly, track status, and process with bounded workers.

Figure 4. Decide sync vs async from the request SLA and work duration.

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Checklist

The maximum acceptable synchronous request duration is defined.
Long-running operations return an explicit job/status contract when needed.
Job submission is idempotent when clients may retry.
Worker concurrency is bounded by downstream capacity.
Job status, failure, retry, timeout, and cancellation semantics are defined.
Poison jobs have a quarantine/dead-letter path.
Polling, callback/webhook, SSE, or WebSocket is chosen based on actual update needs.
Persistent real-time connections have reconnect and fan-out behavior.

Evidence: S39, S40, S41, S42

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