Redisent

Sentinel aware Redis client.

Redisent is a wrapper for the Redis client that fetches configuration details from sentinels.

Instead of passing a Redis URL, you have to pass an array with the URLs of your Redis sentinels as the first parameter, then the name of your master server (as defined in the sentinels configuration) as the second parameter, and finally a hash of options to be used when connecting to the master.

# List of sentinels.
sentinels = ["localhost:27379",
             "localhost:27380",
             "localhost:27381"]

# Master server name as defined in sentinel.conf.
master = "server-1"

redis = Redisent.new(hosts: sentinels, name: master)

If the sentinels can't be reached you will get the exception Redisent::UnreachableHosts. If the master name is unknown, you will get the exception Redisent::UnknownMaster.

In case of a failover, it is important that the clients don't engage with the failed master even if it's restored. For that reason, clients must connect to the Redis sentinels in order to get the address of the promoted master, and the way to accomplish that is by using Redisent.new each time a reconnection is needed.

You can install it using rubygems:

$ gem install redisent