high availability - Redis master/slave replication - single point of failure?

Question

How does one upgrade to a newer version of Redis with zero downtime? Redis slaves are read-only, so it seems like you'd have to take down the master and your site would be read-only for 45 seconds or more while you waited for it to reload the DB.

Is there a way around this?

question from:https://stackoverflow.com/questions/4719346/redis-master-slave-replication-single-point-of-failure

Answer 1

When taking the node offline, promote the slave to master using the SLAVEOF command, then when you bring it back online you set it up as a slave and it will copy all data from the online node.

You may also need to make sure your client can handle changed/missing master nodes appropriately.

If you want to get really fancy, you can set up your client to promote a slave if it detects an error writing to the master.