6. Replication and Sharding for High Availability and Scalability 🌐
MongoDB offers robust mechanisms to ensure data availability and horizontal scalability.
Replication:
- Implements replica sets—groups of MongoDB servers maintaining the same data.
- Provides automatic failover and data redundancy.
- Configuration involves initializing a replica set:
rs.initiate()
- Reads can be distributed across replica members for load balancing.
Sharding:
- Distributes data across multiple servers (shards), enabling horizontal scaling.
- Uses a shard key to partition data.
- Components:
- Shard server
- Config server
- Query router (
mongos
)
- Example of enabling sharding:
sh.enableSharding("mydb")
sh.shardCollection("mydb.users", { _id: 1 })
Together, replication and sharding make MongoDB suitable for enterprise-grade, large-scale deployments, ensuring high availability and performance.