Nicholaos Mouzourakis, Staff Product Security Engineer at Gusto, explains a fascinating performance issue they encountered when deploying Open Policy Agent in Kubernetes. He details how Go's default thread management clashed with Kubernetes CPU resource limits, causing significant performance degradation.

The core issue: Go automatically spawns threads equal to the number of CPU cores reported by the OS (8 in their case), but Kubernetes with a 750 millicore limit only allowed access to 75% of a single core. This meant all 8 Go threads were competing for limited CPU resources, creating what he describes as "context switch thrashing."

Nicholaos shares how they diagnosed this problem and the counterintuitive solution - reducing GOMAXPROCS from 8 to 2 - which immediately improved performance.

Watch the full episode: https://kube.fmhttps://ku.bz/S-2vQ_j-4