Engineers at Vinted discovered that identical servers showed different Redis performance due to Linux clocksource differences. Servers using HPET clocksource instead of the default TSC experienced significantly higher CPU usage and latency. The kernel falls back to HPET when TSC synchronization fails, often after servers are
Table of contents
TL;DRProblemWhat’s a Clocksource?Investigation: What’s Going On?Visual EvidenceBenchmark: The Pain is RealHow to Reproduce (Or Fix) ThisKey TakeawaysSort: