Facebook’s Instagram: Making the Switch to Cassandra from Redis, a 75% ‘Insta’ Savings

Instagram's Infrastructure Software Engineer, Rick Branson, explains how implementing Apache Cassandra significantly reduced costs and improved scalability for their backend systems. Initially using Redis for storing auditing information related to security and site integrity, they switched to Cassandra due to rapidly growing data size and high write rate with low read rate. The transition resulted in a 75% cost reduction and allowed them to add nodes as needed. They also ported their "inboxes" or newsfeed part of the app to Cassandra, which was previously in Redis and faced memory limitations. This move improved durability and reduced costs while maintaining good performance. Branson recommends thoroughly reading Cassandra documentation for successful implementation.