Do virtual nodes solve workload imbalance caused by hot keys?

Do virtual nodes solve workload imbalance caused by hot keys?

• A. No; virtual nodes address structural imbalance but not workload skew.
• B. Yes; virtual nodes guarantee even traffic for every key.
• C. They completely eliminate hot spots by distributing reads evenly.
• D. They remove the need for read replicas.

Answer: (A)

Virtual nodes improve how data is distributed across a cluster by splitting each physical node into many smaller partitions. This helps balance where data lives and makes rebalancing smoother when nodes join or leave. But workload imbalance from hot keys is about access patterns, not just data placement. A single hot key can attract a lot of traffic regardless of how the keys are mapped, so the vnode owning that key can still become a hotspot. So virtual nodes reduce structural imbalance in storage, but they don’t guarantee balanced, skew-free workload for hot keys. To address hot keys, you’d need additional strategies like caching, rate limiting, or traffic-aware replication and routing. Read replicas, while useful for availability and read scalability, tackle a different concern and don’t inherently eliminate hotspots caused by skewed access.

Virtual nodes improve how data is distributed across a cluster by splitting each physical node into many smaller partitions. This helps balance where data lives and makes rebalancing smoother when nodes join or leave. But workload imbalance from hot keys is about access patterns, not just data placement. A single hot key can attract a lot of traffic regardless of how the keys are mapped, so the vnode owning that key can still become a hotspot. So virtual nodes reduce structural imbalance in storage, but they don’t guarantee balanced, skew-free workload for hot keys. To address hot keys, you’d need additional strategies like caching, rate limiting, or traffic-aware replication and routing. Read replicas, while useful for availability and read scalability, tackle a different concern and don’t inherently eliminate hotspots caused by skewed access.