Redis Sentinel : last node doesn't become master
This is a reason to not place your sentinels on your redis instance nodes. Think of them as monitoring agents. You wouldn't place your website monitor on the same node running your website and expect to catch the node death. The same is expected w/Sentinel. The proper route to sentinel...
Simple BASH script to start Redis sentinel
bash offers job control, meaning you can run multiple jobs at the same time, in background. Use & to start a process in background: redis-sentinel /usr/local/redis/sentinel-26379.conf & redis-sentinel /usr/local/redis/sentinel-26380.conf & redis-sentinel /usr/local/redis/sentinel-26381.conf & If you type jobs you'll get a list of running jobs. Note that all the jobs will...
Rails, Redis and Sentinel
ruby-on-rails,redis,redis-sentinel,redis-rails
I may have missed it, but I wasn't aware that you could configure it to read from the slaves? However, this is my master + 2 slave configuration: config.cache_store = :redis_store, { url: 'redis://prestwick/1', sentinels: [{host: 'prestwick.i', port: 26379}, {host: 'carnoustie.i', port: 26379}, {host: 'birkdale.i', port: 26379}], role: 'master', expires_in:...
Using RedisSentinelConfiguration doesn't fail over to the next available sentinel/master
spring,redis,spring-data,spring-data-redis,redis-sentinel
There's a gap between failover and the actual implementation to pick up the newly elected master node. Although Sentinel itself might be configured to failover immediately, the java driver implementation will likely be a bit behind. You'll need to take care of those situations. Running the sentinel example you can...
Is automatic failover built into Redis 2.8?
No, Cluster and Failover are different scenarios. Also Cluster is in 3.0, not 2.8. The standard (and minimum) setup for HA is a master and one slave (aka "a pod"), with a separate set of three nodes which run Sentinel and monitor the pod. This is to ensure failover of...
Can we mark a slave as unpromotable by redis-sentinel?
Yes. In the slave's config file set the slave-priority setting to zero (the number not the word).
ServiceStack.Redis.Sentinel Usage
redis,servicestack,google-compute-engine,sentinel,redis-sentinel
You should only be supplying the host of the Redis Sentinel Server to RedisSentinel as it gets the active list of other master/slave redis servers from the Sentinel host. Some changes to RedisSentinel were recently added in the latest v4.0.37 that's now available on MyGet which includes extra logging and...
sentinels do not recognize master nor themselves
First thing I would check is whether the master requires authentication. If so you need to set that. Once that works, everything else will fall into place as the sentinels will discover at other through the master and the slaves will be detected the same way,
How to manage a situation where designated redis master on a cluster is down on startup
redis,cluster-computing,failover,redis-sentinel
So Redis Cluster which is still in development is meant to solve this exact problem. http://redis.io/topics/cluster-spec Zookeeper, HAProxy and a number other tools could be added to your setup to achieve this automated failover. On its own though Redis with sentinels only self manages a 1 piece of the puzzle....
Redis Sentinel - How to get Config Value?
There is currently no way to do this, since Sentinel does not export a CONFIG command. However if you reach the connection limit, Sentinel will be able to reply with an error about the limit reached, so you can kinda understand if the limit was reached in this way. Of...