Bottleneck Analysis
posts (5)
- CPU in Kubernetes from the kernel up12/12
Anatomy of a CPU problem: from an understated request to p99 latency
One incident end to end: a 500m request, no limit, no throttling, and p99 climbing from 35 to 180 ms. The whole path of the mechanism.
- CPU in Kubernetes from the kernel up11/12
Noisy neighbor and CPU overcommit: when one Pod breaks another
Overcommit works until bursts become correlated. An understated request is not only about placement - it is a weaker position under contention.
- CPU in Kubernetes from the kernel up6/12
PSI: how Linux measures real CPU pressure
Utilisation says how much CPU a workload got. PSI measures the time it lost because it wanted to execute and had nothing to execute on.
- CPU in Kubernetes from the kernel up5/12
CPU Contention: when a process wants CPU and does not get it
With no limit at all a process can sit and wait. All it takes is runnable demand exceeding available capacity - and you only see it in latency.
- series · 12 parts
CPU in Kubernetes from the kernel up
A CPU model built bottom-up: from runnable tasks and the scheduler, through cgroups, requests and limits, to throttling, contention, PSI and diagnostics.