Dealing With Contention medium
What is Head-of-Line (HOL) Blocking in a queue?
- A When the network is fast.
- B When the queue is empty.
- C When the first item in the queue takes a long time to process, causing all subsequent (potentially fast) items to wait unnecessarily.
- D When items are processed in random order.
Answer: C. When the first item in the queue takes a long time to process, causing all subsequent (potentially fast) items to wait unnecessarily.
Common in HTTP/1.1 pipelining or single-threaded workers. HTTP/2 fixes this by multiplexing.
One system design question a day, with spaced repetition so the ones you miss come back.
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