Replication in MongoDB

Configuring replication for high availability

Replication in MongoDB involves maintaining copies of your data across multiple servers, known as a replica set. A replica set consists of primary and secondary nodes, where the primary node handles all write operations, and secondary nodes replicate the data from the primary. This ensures data redundancy and high availability.

Benefits of Replication

Replication provides several benefits:

High Availability: Ensures that your data is always available, even if one or more nodes fail.
Data Redundancy: Protects against data loss by maintaining multiple copies of your data.
Read Scalability: Secondary nodes can handle read operations, reducing the load on the primary node.

Setting Up Replication

To set up replication, follow these steps:

Initialize the Replica Set: Configure the replica set on the primary node.

Example: Initializing Replica Set

rs.initiate()

Add Members to Replica Set: Add secondary nodes to the replica set.

Example: Adding Members

rs.add("secondary1.example.net:27017")
rs.add("secondary2.example.net:27017")

Replication Best Practices

When setting up replication, consider the following best practices:

Deploy replica sets across multiple data centers to protect against regional failures.
Regularly monitor replication lag to ensure secondary nodes are up to date.
Configure appropriate read preferences to balance the load between primary and secondary nodes.
Ensure your application can handle automatic failover by using the MongoDB drivers.