singleflight in Go

crg@crg.eti.br (Cesar Gimenes) — Sat, 13 Jun 2026 09:57:41 -0300

You have an expensive, heavy function. During a traffic spike, six requests arrive at the same time asking for exactly the same thing. With no precautions, you run that function six times to get six identical results.

singleflight is a pattern that collapses those calls. The first call for a key does the real work. Every other call that arrives while it’s in progress waits and gets the same result. One execution, many consumers.

Singleflight on Cesar Gimenes

singleflight in Go