Can you explain the concept of Replica Set and its role in ensuring high availability of the database?

A Replica Set is a group of database servers that maintain copies of the same data to ensure high availability and fault tolerance. In case the primary server fails, one of the secondary servers automatically becomes the new primary, ensuring continuous operation.

Main functions of a Replica Set:

• Data replication between nodes for backup.
• Automatic failover to a secondary node in case of primary failure.
• Increased availability and resilience of the database.

For example, in MongoDB, a Replica Set consists of one primary and several secondary nodes that constantly synchronize data. If the primary fails, one of the secondary nodes becomes the new primary without administrator intervention.