We currently have a redis cache cluster with 3 masters and 3 slaves hosted on 3 windows servers (1 master/slave by server). We are using StackExhange.Redis as our client.
We have RBD disabled but AOF enabled and are experiencing some problems with the cluster in the following situation :
- One of our servers became full and the redis node on this server was unable to write to the AOF file (the error returned to the client was
MISCONF Errors writing to the AOF file: No space left on device). - The cluster did not detect that the node was failing and so did not exlclude it from the cluster.
- All cache operations were blocked until we make some place on the server.
We know that we don't need the AOF, so we have disalbed it after the incident.
But we would like to confirm or infirm our view on redis clustering: for us, if a node was experiencing a failure, the cluster would redirect all requests to another one. We have tested that with a stopped node master, a slave is promoted into a master so we are confident that our cluster is working, but we are not sure why, in our case, the node was not marked as a failure.
Is the cluster capable of detecting a node failure when the failure is only happening when a request is made from a client to the cluster ?