Redis+Redis Object Cache (https://wordpress.org/plugins/redis-cache/) by @tillkruss is the best way to add object-cache to #WordPress, hands down.
#Redis Sentinel is my preferred method for doing HA Redis and I was very happy to see that it is supported by the plugin with a bit of configuration magic.
While configuring the plugin, the only way I found to pass in a password for the sentinel was in the connecting string. This exposes the password in the dashboard. This PR tries to fix that https://github.com/rhubarbgroup/redis-cache/pull/439