1.3.1 Backpressure
Queues with a max depth; HTTP 429; TCP windows. The signal is “stop sending.”
Why it matters
Unbounded buffers become memory leaks, then outages. Dropping on the floor loses data.
How it is used
Bound every queue. Load-shed (reject) when full. In streams, use pull or explicit credits. Measure queue time, not only CPU.