Redis 6.0 entered [EOL](https://endoflife.date/redis) on 2022-05-31, and Redis 6.2 will follow on April 1, 2027 - falling within the GitLab 19.x lifecycle. As with previous Redis versions, we should remove support for Redis 6 to keep our supported version matrix current. A key motivation for doing this work now is our vendored Sidekiq fork. When Sidekiq was upgraded to version 7, [we needed to build a fork](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/142986) to preserve Redis 6 compatibility, as upstream Sidekiq dropped support for it. Removing Redis 6 support allows us to drop this fork and return to upstream Sidekiq, which also unblocks a potential Sidekiq 8 upgrade in the future. ### Open Questions - Timeline for deprecating and removing Redis 6 support (proposed: deprecate in 18.x, remove in 19.0) - This is a breaking change - approved in ~"breaking change::approved" - Plan and timeline for switching back to upstream Sidekiq - Any technical blockers for either change ### Refs - Redis 5: #331468 - Redis 4: #327197 - Redis 3: #213174 - Valkey migration: https://gitlab.com/gitlab-org/omnibus-gitlab/-/work_items/8466