The Underlying Technology of Messages

This post details the technology behind a new version of Facebook Messages that unifies chat, SMS, and email into a real-time conversation. The infrastructure handles over 350 million users and 15 billion messages per month. The team evaluated MySQL, Cassandra, and HBase for storage, ultimately choosing HBase due to its scalability, performance, and simpler consistency model for handling both volatile and long-tail data. They also developed a new application server from scratch to interface with various services like Haystack for attachments and ZooKeeper for user discovery, ensuring a robust and performant real-time messaging system.