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Exam Question Walkthrough: High Availability for Relational Databases
Learn how to tackle AWS SAA-C03 questions on database availability and failover with this detailed walkthrough.
A common decision point for candidates is understanding how to ensure high availability and durability for relational workloads. This question tests your knowledge of AWS database options and their capabilities.
The question
A company needs a database that automatically replicates across three Availability Zones and can fail over in seconds with no data loss for a relational workload. Which option is BEST?
- A. Amazon RDS Single-AZ
- B. Amazon Aurora with Multi-AZ
- C. Amazon DynamoDB
- D. Amazon Redshift
Think before you scroll
Before looking at the answer, consider what features are essential for a relational database needing high availability. Focus on replication, failover capabilities, and the specific requirements of relational workloads.
The answer
B. Amazon Aurora with Multi-AZ is the correct option. Aurora automatically replicates data across three Availability Zones and supports fast failover. This ensures high availability and minimal data loss, making it ideal for relational workloads.
Why the other options lose
- A. Amazon RDS Single-AZ: This option only runs in a single Availability Zone and does not support automatic failover. Therefore, it cannot meet the requirement for high availability without manual intervention.
- C. Amazon DynamoDB: While DynamoDB is a highly available NoSQL database, it is not a relational database. This question specifically asks for a solution suited for relational workloads, disqualifying DynamoDB.
- D. Amazon Redshift: Redshift is designed for data warehousing and analytics, not for traditional relational workload scenarios requiring immediate failover and replication across Availability Zones. It lacks the necessary features for this use case.
The concept behind it
High availability for relational databases often involves using Multi-AZ deployments, which ensure data is replicated across multiple locations. Understanding the specific features of AWS services, like Amazon Aurora, is key to selecting the right option for resilience and durability in your architecture.
Exam trap to remember
Remember: Multi-AZ deployments are essential for high availability in relational databases. Single-AZ options do not provide the failover capabilities necessary for critical systems.