At Instagram, they’re using Redis (comparable to Memcached, but with more options) to map photoIds to userIds. After tweaking their setup — by using Redis hashes (dictionaries that are can be encoded in memory very efficiently) — in Redis, they’ve brought memory usage down from 70MB to 16MB to store 1,000,000 records. While prototyping this …
Continue reading “Storing hundreds of millions of simple key-value pairs in Redis”