Designing a Unique ID Generator in Distributed Systems
· 6 min read
Generating a unique ID sounds trivial—until your system scales across hundreds or thousands of servers.
Most developers begin with auto-increment IDs in a relational database. It works perfectly for a single database instance. But in distributed systems, generating unique identifiers becomes a fundamental design challenge.
Platforms like Instagram, Amazon, Uber, and WhatsApp generate millions of new objects every day—users, orders, messages, rides, and payments. Every object must receive a globally unique identifier, even when thousands of servers are creating data simultaneously.
The challenge isn't generating numbers.
The challenge is generating billions of unique, scalable, fault-tolerant, ordered IDs without creating a bottleneck.