/plushcap/analysis/cloudflare/keepalives-considered-harmful

Keepalives considered harmful

What's this blog post about?

This article discusses an unexpected solution to sporadic latency spikes experienced by Cloudflare's edge stack. The author explains that disabling keepalives between SSL and FL (two parts of their edge stack) improved the 99.9th latency percentile by 4x. Although generally beneficial, in this specific case, the local connection establishment was faster than the delay caused by landing on a busy worker. This solution allowed Cloudflare to run their machines hotter without seeing increased latency, reducing their overall footprint.

Company
Cloudflare

Date published
March 19, 2020

Author(s)
Ivan Babrou

Word count
2064

Hacker News points
None found.

Language
English


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