SYSE.40:2 - Problem

Requests with the same name or arrival rate can consume very different CPU, memory, storage, connection or worker resources. A long queue can hide overload until every accepted task misses its useful deadline. Retries can multiply demand while the original work is still running.

Adding capacity may not repair a serial bottleneck, a downstream limit or a failure that affects every new instance. Likewise, protecting a front-end proxy does not automatically protect its upstream service or preserve the user’s task.