Cassandra medium
Why is the use of Virtual Nodes (VNodes) preferred over the legacy single-token architecture during a 'Node Expansion' or 'Node Failure' scenario?
- A VNodes allow a node to store 256x more data than a single-token node.
- B Parallelization: Since a node's data is split into many small ranges, a new node can stream its initial data from *all* existing nodes simultaneously, instead of bottlenecking on just its two neighbors.
- C VNodes automatically encrypt data using a different algorithm for each token range.
- D VNodes eliminate the need for any replication factor.
Answer: B. Parallelization: Since a node's data is split into many small ranges, a new node can stream its initial data from *all* existing nodes simultaneously, instead of bottlenecking on just its two neighbors.
In the old 'One Token' world, if you added a node, its neighbors would be crushed by the streaming load. With VNodes (typically 256 per server), the responsibilities are shuffled. The rebuild workload is spread across the entire cluster, making management much safer and faster.
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