A message is delivered, acknowledged and gone. Treating the queue as a record of what happened means the record disappears as it is processed, and there is nothing…
basic_publish returns as soon as the message is written to the socket. The broker may not have accepted it, may not have routed it anywhere, and may have…
Every current browser and Node 8 ship async functions, which means the transform is no longer the reason for a build step — although the build step is…
A distributed transaction is not available, so the pattern is: do each step, and if a later one fails, run compensating actions to undo the earlier ones. Compensation…
The synchronous call between two services was the reason both were down. Publishing an event decouples their availability — and makes eventual consistency a business decision.
The queue worker’s –timeout and the connection’s retry_after are two different clocks, and getting their order wrong is the most common cause of a job silently running twice.…
A 400ms pause on every request, once an hour, caused by a cache cleanup nobody thought of as expensive. Redis is single-threaded, and freeing memory is work.
Reads moved to a replica and checkout started showing empty carts. Read-after-write, sticky connections, and measuring the lag rather than assuming it.
Redis is single-threaded, so DEL on a structure with a million members blocks every other client for as long as freeing it takes — which is milliseconds for…