Read replicas in GCP - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Read Replica Purpose

What is the primary purpose of using read replicas in a cloud database environment?

A To provide automatic failover for the primary database in case of failure

B To improve read scalability by offloading read queries from the primary database

C To increase the write throughput by distributing write operations across replicas

D To encrypt data at rest for enhanced security

💡 Hint

Think about how read replicas help with handling many users reading data simultaneously.

Read replicas are used to improve read scalability by handling read queries, reducing load on the primary database which handles writes.

❓ Architecture

intermediate

Read Replica Deployment Architecture

In Google Cloud SQL, which architecture best describes the placement of read replicas relative to the primary instance?

A Read replicas are deployed in the same zone as the primary instance only

B Read replicas are automatically deployed on-premises for disaster recovery

C Read replicas can be deployed in different zones or regions to improve availability and latency

D Read replicas must be deployed in a different project than the primary instance

💡 Hint

Consider how cloud providers use zones and regions to improve fault tolerance and performance.

Google Cloud SQL allows read replicas to be deployed in different zones or regions to improve availability and reduce latency for users in different locations.

❓ service_behavior

advanced

Read Replica Lag Behavior

What is the expected behavior of a read replica in Google Cloud SQL when the primary database experiences a sudden spike in write operations?

A The read replica may experience replication lag, causing it to serve slightly outdated data temporarily

B The read replica immediately reflects all new writes with zero delay

C The read replica stops serving read requests until it catches up with the primary

D The read replica automatically converts to a primary instance to handle the write spike

💡 Hint

Think about how data replication works asynchronously in cloud databases.

Read replicas replicate data asynchronously, so during high write activity, they may lag behind the primary and serve slightly outdated data temporarily.

❓ security

advanced

Securing Read Replicas

Which security best practice should be applied when configuring read replicas in Google Cloud SQL?

A Store read replica credentials in plaintext within application code

B Disable SSL connections to improve performance between primary and replicas

C Allow all IP addresses to connect to replicas for easier access

D Use private IP connectivity and restrict network access to authorized clients only

💡 Hint

Consider how to protect data in transit and limit access to trusted sources.

Using private IP and restricting network access ensures secure communication and limits exposure of read replicas to unauthorized users.

✅ Best Practice

expert

Optimizing Read Replica Usage

You have a Google Cloud SQL primary instance with multiple read replicas. Which strategy best optimizes read traffic distribution to improve performance and reduce latency?

A Use a load balancer or application logic to distribute read queries evenly across all read replicas

B Configure replicas to accept write queries to balance load

C Direct all read queries to the primary instance to ensure data freshness

D Disable read replicas during peak hours to reduce replication lag

💡 Hint

Think about how to spread workload evenly to avoid bottlenecks.

Distributing read queries evenly across replicas balances load, improves performance, and reduces latency by preventing any single replica from becoming a bottleneck.