In Cassandra all nodes are equal, but specific nodes hold specific parts of data. The only concept is the coordinator node which is the node that got the query. All nodes can handle all queries. The coordinator node is different per request.
Comment on If "Master/Slave" terminology in computing sounds bad now, why not change it to "Dom/Sub"?
dragonlobster@programming.dev 4 weeks agoFor a distributed database there is also fragmentation/sharing though. In this case calling the nodes replicas is not accurate. I guess you would call these “shard” or “dsta” nodes.
You are right about the “slaves” not behaving, in fact they jump on the chance to become the “master” themselves once the current “master” goes down. Then there is the split-brain problem.
It’s really more like a worker boss relationship, but I would hesitate to call database nodes “workers” because this one is usually used for a processing engine like Spark.
JackbyDev@programming.dev 4 weeks ago
Semi_Hemi_Demigod@lemmy.world 4 weeks ago
A lot of distributed databases use the concept of quorum to prevent split-brain. Does that make them a kind of democracy?
maniii@lemmy.world 4 weeks ago
Usually quorum is maintained by using odd numbering so that when one node fails the next sequential node assumes the role allowing quorum-election breaking any ties.
JackbyDev@programming.dev 4 weeks ago
It depends, there are too many different databases to say they all use that approach.