<!--IssueSummary start--> <details> <summary> Everyone can contribute. [Help move this issue forward](https://handbook.gitlab.com/handbook/marketing/developer-relations/contributor-success/community-contributors-workflows/#contributor-links) while earning points, leveling up and collecting rewards. </summary> - [Close this issue](https://contributors.gitlab.com/manage-issue?action=close&projectId=278964&issueIid=18346) </details> <!--IssueSummary end--> ### Background: file `lib/gitlab/mail_room.rb` contains ``` if gitlab_redis.sentinels? config[:sentinels] = gitlab_redis.sentinels end ``` This code is too tightly coupled to an implementation detail of the pubsub functionality and should be moved into the connection pool management rather than its client. **What questions are you trying to answer?** increase long term maintainability of code **What do you already know about the areas you are exploring?** **What does success look like at the end of the project?** Code to configure connections to sentinels should be moved into the connection pool classes. ### Links / references: gitlab-ce~3011693