MongoDB Sharding Basics: How Does Data Sharding Enable Database Scaling?

MongoDB sharding is used to address single-server bottlenecks caused by increasing data volume by horizontally scaling to split data. Data is routed to different shard servers based on shard keys (range or hash strategies). Core components include the query router (mongos, which forwards requests), config servers (which store metadata), and shard servers (which store data). Sharding can enhance storage capacity (by distributing data across multiple servers), parallel read/write performance, and support flexible resource allocation. The selection of shard keys is crucial and must be aligned with business query requirements to avoid performance imbalance. At its core, sharding separates routing from storage, enabling on-demand scaling and breaking through single-server limitations, making it a key solution for MongoDB's efficient capacity expansion.