Quorum

Mirrored and Quorum Queues

Understand the deprecated classic mirrored queue model and why quorum queues, built on the Raft consensus algorithm, are now the recommended way to achieve hig…

What Is the Split-Brain Problem in Distributed Databases?

Split-brain occurs when a network partition or failed failover causes two nodes in a distributed database cluster to each believe they are the sole primary and…

How to Design a Distributed Key-Value Store

A distributed key-value store is designed by partitioning keys across nodes with consistent hashing, replicating each key to N nodes for fault tolerance, and c…

Strong Consistency vs Eventual Consistency: How Do You Choose?

Strong consistency guarantees that every read returns the most recently written value across all replicas, typically by requiring writes and reads to coordinat…

What is the Raft Consensus Algorithm?

Raft is a consensus algorithm that lets a cluster of nodes agree on a single, replicated sequence of operations by electing one leader per term who owns all wr…

What is the Paxos Consensus Algorithm?

Paxos is a consensus algorithm that lets a group of nodes agree on a single value even with failures and message loss, using two phases (prepare/promise, then…