This call fails nearly immediately when the node actually goes offline. Note that detection of a node going down should be nearly instantaneous, since the mechanism used to keep tabs on a node is via a blocking Redis BLPOP call (no polling). If so, the newly available nodes will be configured as slaves and brought back into the list of available nodes. All nodes marked as unavailable will be periodically checked to see if they have been brought back online. All existing slaves will be automatically reconfigured to point to the new master for replication. If the node that went offline was the master, then one of the slaves will be promoted as the new master. As soon as a node is detected as being offline, it will be moved to an 'unavailable' state. Background watchers are setup for each of the redis nodes. When the daemon starts up, it automatically discovers the current master/slaves. One or more Node Manager daemons run as background processes and monitor all of your configured master/slave nodes. This gem (built using ZK) attempts to address these failover scenarios. When using master/slave replication, it is desirable to have all writes go to the master, and all reads go to one of the N configured slaves. The existing standard Redis client for Ruby also only supports configuration for a single Redis server. This manual switch-over is not desirable in high traffic sites where Redis is a critical part of the overall architecture. When the master node dies, a new master must be manually brought online and assigned as the slave's new master. Redis does not currently provide an automatic failover capability when configured for master/slave replication.

Redis_failover provides a full automatic master/slave failover solution for Ruby. Redis_failover - redis_failover is a ZooKeeper-based automatic master/slave failover solution for Ruby

Redis desktop manager dmg