What is Apache Cassandra?
Answer
Apache Cassandra is an open-source, highly scalable, distributed NoSQL database designed for handling massive amounts of data across many commodity servers with no single point of failure. Originally developed at Facebook for Inbox Search, it was open-sourced in 2008. Cassandra combines key features from Amazon Dynamo (distributed architecture, eventual consistency, tunable consistency) and Google Bigtable (column-family data model). Key characteristics: Linear scalability: add nodes to increase throughput proportionally. High availability: no master node — all nodes are equal. Tolerates node failures without downtime. Tunable consistency: configure per-query between strong and eventual consistency. Wide-column store: data organized in tables with flexible column structure. Used by Netflix, Apple, Discord, Instagram, and thousands of other companies for high-write, high-read workloads requiring 100% uptime.