How to add Redis sentinel to my already existing master-slave Redis?

Question

Here is my situation : I have an existing master-slave Redis architecture (2 different servers).

I want to add Redis sentinel to be able to use the automatic failover, but I don't want any downtime in production. As sentinel needs to know the master, but as I need to restart Redis to be able to start sentinel (thus switching the master and slave), how can I do that without having a downtime?

Answer 1

You don't restart existing redis instances to start sentinel. Sentinel runs as a separate process on different machines. You set up a sentinel constellation then tell sentinel about the master in your pod and it manages it from there.