After posting about Spreecast’s Redis High Available/Failover solution based on ZooKeeper where I referred to Redis Sentinel, I realized I haven’t linked to Salvatore Sanfilippo’s post about the design of Redis Sentinel:
It is a distributed monitoring system for Redis. On top of the monitoring layer it also implements a notification system with a simple to use API, and an automatic failover solution.
Well, this is a pretty cold description of what Redis Sentinel is. Actually it is a system that also tries to make monitoring fun! In short you have this monitoring unit, the Sentinel. The idea is that this monitoring unit is extremely chatty, it speaks the Redis protocol, and you can ask it many things about how it is seeing the Redis instances it is monitoring, what are the attached slaves, what the other Sentinels monitoring the same system and so forth. Sentinel is designed to interact with other programs a lot.
The official Redis Sentinel documentation is available too here. Salvatore Sanfilippo is actively working on Redis Sentinel and while it is not complete yet, there are already users trying it out. Redis Sentinel will be stable in a few weeks and will be released as part of the Redis 2.8. In case you’ll want to start using it before 2.8 becomes available, use the git unstable branch
Original title and link: Redis High Availability and Automatic Failover: Redis Sentinel ( ©myNoSQL)