Closing HA gaps in a redis-sentinel + haproxy setup

TL;DR: A common haproxy-in-front-of-redis-sentinel setup will cascade-restart its haproxy pods during sentinel failover if the kubernetes liveness probe checks backend health. The probes need splitting: liveness reflects process aliveness, readiness reflects backend availability. I also had to add a preStop hook that runs kill -USR1 1 so haproxy can drain existing connections before kubelet sends SIGTERM, which is a hard stop in haproxy 3.x. The setup Link to heading A small redis high-availability cluster: