Problem Statement
What are the essential best practices for deploying MongoDB in production environments?
Explanation
Deploying MongoDB in production requires careful planning and adherence to best practices to ensure reliability, performance, and security. These practices span architecture, configuration, operations, and monitoring.
First, always use replica sets even for single-server deployments. Replica sets provide high availability through automatic failover and data redundancy. Use at least three data-bearing members across different availability zones or data centers for maximum resilience. Configure appropriate write and read concerns based on your durability requirements.
Second, properly size your hardware and infrastructure. Ensure your working set fits in RAM for optimal performance. Working set is the frequently accessed data and indexes. MongoDB performance degrades significantly when the working set exceeds available memory. Use SSD storage for data directories to improve I/O performance. Allocate sufficient CPU cores for concurrent operations.
Third, implement comprehensive monitoring and alerting. Track key metrics including query performance, replication lag, connection counts, memory usage, disk I/O, and error rates. Set up alerts for abnormal conditions like high replication lag, low disk space, or connection saturation. Use MongoDB Cloud Manager, Ops Manager, or integrate with tools like Prometheus and Grafana.
Fourth, establish backup and disaster recovery procedures. Implement automated backups with point-in-time recovery capability. Test restore procedures regularly to verify backups work. Store backups in a different geographic location. Document recovery time objectives and recovery point objectives, and ensure procedures meet these targets.
Fifth, implement security hardening. Enable authentication and authorization, use TLS for all connections, implement network security through firewalls and VPNs, enable encryption at rest for sensitive data, configure auditing for compliance, and keep MongoDB updated with security patches.
Sixth, optimize for your workload. Create appropriate indexes based on query patterns, but avoid over-indexing which slows writes. Use covered queries where possible. In sharded clusters, choose shard keys carefully to ensure even distribution and support common queries.
Seventh, manage connection pooling properly. Configure appropriate connection pool sizes in drivers to balance concurrency with resource usage. Monitor connection counts and adjust pool sizes if needed. Finally, document your deployment architecture, configurations, and operational procedures for your team.