What happen when use both Cluster and Sentinel?

[Lumos Dang]

hi guys,

Last few days, I thought about using Redis Cluster with Sentinel but hard to find any tested solution on Google.

What happen when use both Cluster and Sentinel, for example:

3 x Redis Masters (join by redis-trib.rb with replication = 0, mean cluster without replication)

3 x Redis Slaves for each Master, mean 9 slave instances)

3 x Sentinels (1 sentinel for each master)

If one of master (Master #2)  goes down, is its sentinel (Sentinel #2) promote one of its slaves to master and rejoin to cluster with other masters (Master #1, Master #3) ?

Thanks,

Lumos Dang

[Jan-Erik Rediger]

All hell breaks lose and you are completely on your own.
Don't do it.
https://fnordig.de/2015/06/01/redis-sentinel-and-redis-cluster/index.html

Cluster already handles failover on its own.

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[Salvatore Sanfilippo]

On Fri, Aug 4, 2017 at 11:22 AM, Jan-Erik Rediger <jan...@fnordig.de> wrote:

> All hell breaks lose and you are completely on your own.

That's a very precise description of what happens indeed...

--
Salvatore 'antirez' Sanfilippo
open source developer - Redis Labs https://redislabs.com

"If a system is to have conceptual integrity, someone must control the
concepts."
— Fred Brooks, "The Mythical Man-Month", 1975.

[hva...@gmail.com]

Sentinel is designed to be used with the non-Cluster (non-sharded) configuration of Redis.  Redis Cluster (sharded) was designed to work independently without Sentinel.  If you try to use Sentinel with Redis Cluster, the automated actions of Sentinel will conflict with the automated actions built into Redis Cluster and you will get chaos and outages.

It's a DDT situation.  (DDT = Don't Do That)