.NET Architecture & System Design Interview Question #61

What is a hot partition or hot shard?

Database Scaling, Partitioning, NoSQL & Data Consistency Mid-Level Intermediate

Quick Interview Answer

A hot partition is a partition that receives disproportionately high traffic or data compared with others. It can become the system bottleneck even when total capacity across all partitions is large.

Detailed Explanation

A hot partition is a partition that receives disproportionately high traffic or data compared with others. It can become the system bottleneck even when total capacity across all partitions is large.

Hot spots can result from sequential keys, one very large tenant, time-based traffic concentration, or a poor partition strategy. Mitigations include changing the key, adding bucketing, isolating large tenants, or redistributing data.

Code Example

Shard A: 10% load
Shard B: 15% load
Shard C: 70% load  <- hot
Shard D: 5% load