MongoDB's document-oriented model and flexible schema have made it popular for web applications that need rapid development cycles and horizontal scalability. However, running MongoDB reliably in production requires understanding its replication, sharding, and operational management features.
Production Deployment Best Practices
Always deploy MongoDB in a replica set configuration, even for single-server deployments. A replica set consists of a primary node that receives writes and one or more secondary nodes that replicate data asynchronously. If the primary fails, the replica set automatically elects a new primary, providing automatic failover. Use an odd number of voting members (typically three or five) to ensure clean election results.
Sharding distributes data across multiple replica sets to handle datasets and write volumes that exceed the capacity of a single replica set. Choose a shard key that distributes data evenly and aligns with your query patterns. A poorly chosen shard key can create hot spots where one shard handles a disproportionate share of traffic while others sit idle.
Monitor MongoDB performance using the built-in serverStatus and currentOp commands, and integrate with monitoring tools like MMS (MongoDB Management Service) for historical metrics and alerting. Pay close attention to page faults, which indicate that the working set exceeds available RAM, and replication lag, which affects read consistency from secondaries. Implement regular backups using mongodump or filesystem snapshots of the data directory.