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cassandra

How long will it take to remove one node from a Cassandra cluster?

I'm new to Cassandra. I would like to know how long it takes me to remove a node from the cluster. What factors influence and is there a formula in general? There is no difference how many nodes there are in the cluster, for example, 4 nodes with 20 GB of workload. If you remove one node, how long will Cassandra work out this process?

Solution

  • How long it takes to decommission a node from a Cassandra cluster depends on a lot of moving parts which include (but not limited to):

    • data density (size of data to stream to neighbouring nodes)
    • hardware capacity (CPU, RAM, disk type, etc)
    • how busy the cluster is (access patterns)
    • network IO bandwidth, capacity
    • data model
    • disk IO bandwidth, capacity

    The quick answer is -- it depends on your environment.

    The only way to find out is to do your own tests on identical hardware, identical infrastructure configuration, and as close to production workloads as possible. Cheers!