https://brtkwr.com/tags/haproxy/Recent content in Haproxy on brtkwr.comHugoenThu, 14 May 2026 10:00:00 +0000https://brtkwr.com/posts/2026-05-14-closing-ha-gaps-in-redis-sentinel-haproxy/Thu, 14 May 2026 10:00:00 +0000https://brtkwr.com/posts/2026-05-14-closing-ha-gaps-in-redis-sentinel-haproxy/<p><strong>TL;DR:</strong> 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 <code>preStop</code> hook that runs <code>kill -USR1 1</code> so haproxy can drain existing connections before kubelet sends <code>SIGTERM</code>, which is a hard stop in haproxy 3.x.</p> <h2 id="the-setup"> The setup <a class="heading-link" href="#the-setup"> <i class="fa-solid fa-link" aria-hidden="true" title="Link to heading"></i> <span class="sr-only">Link to heading</span> </a> </h2> <p>A small redis high-availability cluster:</p>