Horizontal Scaling

What is Database Sharding?

Database sharding is a horizontal partitioning technique that splits a large dataset across multiple independent database servers (shards), where each shard ho…

How Do You Choose a Sharding Key?

A good sharding key is a column with high cardinality and an even, predictable value distribution that matches your query patterns, so writes and reads spread…

What is Range-Based Sharding?

Range-based sharding assigns rows to shards based on contiguous ranges of the shard key's value, so each shard owns a specific, ordered slice such as user IDs…

What is Hash-Based Sharding?

Hash-based sharding applies a hash function to the shard key and uses the result (typically modulo the shard count) to assign each row to a shard, which spread…

What is Consistent Hashing and Why Do Databases Use It?

Consistent hashing maps both shard keys and shard servers onto the same circular hash space, so each key is owned by the next server found clockwise on the rin…

What Challenges Arise When Resharding and Rebalancing a Database?

Resharding, moving data to a new number of shards or a better key layout, is challenging because it must move large volumes of live data without downtime, keep…

How Do You Approach Database Capacity Planning?

Database capacity planning means forecasting future storage, throughput, and connection needs from current growth trends and peak-load patterns, then provision…

How Does MongoDB Sharding Architecture Work?

MongoDB sharding distributes a collection’s documents across multiple shards (each a replica set) using a shard key, coordinated by lightweight mongos routers…

Horizontal vs Vertical Scaling

Vertical scaling (scaling up) means adding more power — CPU, RAM or disk — to a single machine, while horizontal scaling (scaling out) means adding more machin…

Sharding vs. Partitioning: What is the Difference?

Partitioning is the general act of splitting a dataset into smaller pieces by some rule, while sharding is a specific form of horizontal partitioning where tho…

What is Auto-Scaling and How Does it Work?

Auto-scaling is the automated process of adjusting the number of running compute instances up or down based on real-time demand signals such as CPU utilization…

Horizontal vs Vertical Scaling: What is the Difference?

Vertical scaling (scaling up) adds more CPU, memory, or disk to a single existing machine, while horizontal scaling (scaling out) adds more machines that share…