Sharded vs. Distributed: The Math Behind Resilience and High Availability

Probability is the branch of mathematics that deals with uncertainty. It helps us understand the likelihood of different outcomes occurring. Below, we consider two alternative architecture options for scaling a database horizontally and employ probability theory to show that one architecture is more reliable than the other by a factor of 60,000.

Horizontal Database Scaling Architecture Options

Application-Level Sharding

Application-level sharding uses domain-specific knowledge to partition data into multiple database instances running on…