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Difficulty: HardImproving Database and Caching Efficiency

A sports broadcasting network hosts a live streaming platform where real-time game metadata is stored in an Amazon RDS for PostgreSQL DB instance. During major sporting events, concurrent user requests spike tenfold, causing CPU utilization on the database to reach 98%98\% and metadata query response times to degrade from 5050 milliseconds to over 55 seconds. The application team notes that the query workload is highly repetitive and read-heavy. The solutions architect must implement a caching solution that achieves sub-millisecond query latency, supports automatic replication and node failover across multiple Availability Zones, and provides the ability to persist cache snapshots to Amazon S3. Which architecture should the solutions architect implement to resolve the performance bottleneck?

  1. Deploy an Amazon ElastiCache for Redis replication group in a Multi-AZ configuration with automatic failover enabled.Answer
  2. B
    Deploy an Amazon ElastiCache for Memcached cluster with nodes distributed across multiple Availability Zones.
  3. C
    Deploy an Amazon RDS Multi-AZ standby instance in a secondary Availability Zone and configure the application to load-balance read queries to the standby instance.
  4. D
    Deploy a single-node Amazon ElastiCache for Redis instance with automated backups, and configure an AWS Lambda function to restore the cache from snapshots in a secondary Availability Zone upon node failure.

Answer

Deploy an Amazon ElastiCache for Redis replication group in a Multi-AZ configuration with automatic failover enabled.
The correct solution uses Amazon ElastiCache for Redis in a Multi-AZ replication group. This deployment model provides the sub-millisecond query performance required by the platform, replicates data across multiple Availability Zones, supports automatic failover if the primary node fails, and enables snapshot persistence directly to Amazon S3.

Step-by-Step Solution

1
Analyze the workload requirements and identify that the database is experiencing read-heavy performance degradation due to repetitive metadata queries.
Confirming that an in-memory caching layer is the correct pattern to offload reads from the database and achieve sub-millisecond latency.
Caching addresses the high CPU utilization caused by repetitive read queries.
2
Evaluate ElastiCache engines (Redis vs. Memcached) against the requirements of replication, automatic failover, and snapshot persistence.
ElastiCache for Redis is selected because ElastiCache for Memcached does not support replication, Multi-AZ failover, or persistence features.
Redis provides the required high availability, failover capabilities, and S3 snapshot integration.
3
Design the Redis deployment topology using a Multi-AZ configuration with automatic failover.
A multi-node replication group distributed across Availability Zones is selected.
This configuration satisfies the requirement for automatic node failover and high availability with minimal operational overhead.

Key Concept

Selecting the appropriate caching engine and configuration to support high availability, replication, and persistence under high read loads.
Estimated Time:2m 30s
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Topics

Improving Database and Caching Efficiency