Primary and secondary nodes in MongoDB - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a primary node in MongoDB?

A primary node is the main server in a MongoDB replica set that receives all write operations. It replicates data to secondary nodes.

beginner

What is a secondary node in MongoDB?

A secondary node is a server in a MongoDB replica set that copies data from the primary node and can serve read operations.

beginner

Why does MongoDB use primary and secondary nodes?

To ensure data is safe and available. The primary handles writes, and secondaries keep copies to protect against failure and allow reads.

intermediate

What happens if the primary node fails in MongoDB?

The replica set automatically elects a new primary from the secondary nodes to keep the database working without interruption.

beginner

Can secondary nodes accept write operations directly?

No, only the primary node accepts writes. Secondary nodes replicate data from the primary and can serve reads if configured.

What role does the primary node play in a MongoDB replica set?

A Elects secondary nodes

B Handles all write operations

C Only serves read operations

D Backs up data to cloud

The primary node handles all write operations and replicates data to secondary nodes.

What is the main purpose of secondary nodes?

A To elect the primary node

B To accept write operations

C To replicate data from the primary

D To delete old data

Secondary nodes replicate data from the primary node to keep copies of the data.

If the primary node fails, what happens next?

A A secondary node is elected as the new primary

B The database stops working

C All data is lost

D The primary node repairs itself automatically

MongoDB elects a new primary from the secondary nodes to maintain availability.

Can secondary nodes serve read requests in MongoDB?

A Only for write operations

B No, only primary nodes can serve reads

C Only during primary failure

D Yes, if configured to do so

Secondary nodes can serve read requests if the system is set up to allow it.

Which node type in MongoDB replica set accepts write operations?

A Primary node

B Secondary node

C Both primary and secondary

D Neither primary nor secondary

Only the primary node accepts write operations in a MongoDB replica set.

Explain the roles of primary and secondary nodes in a MongoDB replica set.

Think about who writes data and who copies it.

Describe what happens during a primary node failure in MongoDB.

Focus on failover and election process.