Database replication (master-slave) in HLD - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main purpose of master-slave database replication?

To copy data from the master database to one or more slave databases to improve read performance and provide data redundancy.

beginner

In master-slave replication, which database handles write operations?

The master database handles all write operations, while slaves handle read operations.

intermediate

What is a common challenge in master-slave replication related to data consistency?

Slaves may lag behind the master, causing eventual consistency rather than immediate consistency.

intermediate

How does asynchronous replication differ from synchronous replication in master-slave setups?

Asynchronous replication allows the master to continue without waiting for slaves to confirm data receipt, while synchronous waits for confirmation, ensuring stronger consistency but higher latency.

intermediate

Name one advantage and one disadvantage of master-slave replication.

Advantage: Improves read scalability by distributing reads to slaves. Disadvantage: Single point of failure at the master and potential data lag on slaves.

In master-slave replication, which database is responsible for processing write requests?

A Master

B Slave

C Both master and slave

D Neither

The master database handles all write operations, while slaves handle read operations.

What is a common issue caused by asynchronous replication in master-slave setups?

A Master cannot accept reads

B Slaves block writes

C Slaves may have outdated data temporarily

D Slaves overwrite master data

Asynchronous replication can cause slaves to lag behind the master, leading to temporary outdated data.

Which of the following is NOT a benefit of master-slave replication?

A Automatic failover without configuration

B Improved read scalability

C Data redundancy

D Load distribution for reads

Master-slave replication does not provide automatic failover by default; additional setup is needed.

What happens if the master database fails in a typical master-slave setup without failover?

A Reads and writes continue normally

B Slaves automatically become masters

C Slaves reject all queries

D Writes stop until master is restored

Without failover, the master failure stops all write operations until it is fixed.

Which replication type waits for slaves to confirm data receipt before completing a write?

A Multi-master replication

B Synchronous replication

C Master-slave replication

D Asynchronous replication

Synchronous replication waits for slaves to confirm data receipt, ensuring stronger consistency.

Explain how master-slave replication works and its main benefits and drawbacks.

Think about who writes and who reads, and what happens if the master fails.

Describe the difference between synchronous and asynchronous replication in a master-slave database system.

Consider how quickly the master waits for slaves before confirming writes.