๐๐ญโ๐ฌ ๐ญ๐ก๐ ๐๐ข๐ซ๐ฌ๐ญ ๐๐จ๐ง๐๐๐ฒ ๐จ๐ ๐ญ๐ก๐ ๐ก๐จ๐ฅ๐ข๐๐๐ฒ๐ฌ. ๐๐ฏ๐๐ซ๐ฒ ๐๐ฅ๐ข๐ ๐ก๐ญ ๐ฅ๐๐๐ฏ๐๐ฌ ๐๐๐๐จ๐ซ๐ 9๐๐ฆ.
Thousands of passengers reach airport security at once.
Imagine the airport let everyone through the entrance together. People crowd the scanners. Bags pile up. Staff canโt move. Nobody gets through, and everyone misses their flight.
Real airports donโt do that. They control the flow at the door: a rope queue, a gate that opens in batches, a fast-track lane for anyone about to miss a flight. The scanners keep a steady pace, and the queue absorbs the rush.
Software faces the same rush on payday, during a flash sale, or when something goes viral. A system that accepts everything eventually serves no one.
Engineers call the fix ๐๐๐๐ค๐ฉ๐ซ๐๐ฌ๐ฌ๐ฎ๐ซ๐. I sketched how it works, from the API gateway down to the database.
Whatโs the biggest traffic spike your system has had to survive?
Top comments (2)
Nice analogy. The airport rope queue is bounded, and that's the detail worth emphasizing. An unbounded queue just moves the crash from the scanners to the hallway. Real backpressure means someone gets told "not now": rate limits at the gateway, bounded queues in between, load shedding when even the queue is full. And the other half of the fix is client behavior: retries with exponential backoff and jitter, so a thousand clients don't come back in sync and recreate the spike you just shed.
The airport door analogy works well here. Letting everyone in at once just moves the crash to the scanners.