Backpressure
A slow consumer signaling upstream to slow down, instead of buffering work until memory or the queue runs out.
If producers outpace consumers, an unbounded buffer grows until something crashes, often far from the cause. Backpressure makes the limit visible: bounded queues that refuse new items, streams that pull rather than push, rate limits returned to callers, and consumers that fetch the next batch only when ready. Combined with load shedding, it keeps an overloaded system slow rather than dead.
Related terms
- Load shedding: Rejecting some requests on purpose when a system is overloaded, so the rest still get served instead of everything grinding to a halt.
- At-least-once delivery: A queue or broker guarantee that every message arrives, possibly more than once, so consumers must handle duplicates.
- Bulkhead pattern: Giving each dependency or workload its own limited pool of connections or workers, so one slow part cannot use up everything.
