Seven Databases in Seven Weeks, 2nd Edition

Day 3: Replica Sets, Sharding, GeoSpatial, and GridFS

Mongo has a powerful ability to store and query data in a variety of ways. But then again, other databases can do those things, too. What makes document databases unique is their ability to efficiently handle arbitrarily nested, schemaless data documents. Thus far, we’ve run Mongo as a single server. But if you were to run Mongo in production, you’d want to run it as a cluster of machines, which would provide for much higher availability and enable you to replicate data across servers, shard collections into many pieces, and perform queries in parallel.

Replica Sets

Mongo was meant to scale ...