Use Amazon ElastiCache with a supplied product application. Three guided labs teach cache-aside, fresh prices and cache-failure handling; an independent challenge asks you to repair stale prices without clearing unrelated cached data.
What You Will Learn
- Create a standalone Valkey node and connect the application to its actual endpoint.
- Observe misses, hits and source-read counts; compare cached values with authoritative DynamoDB records.
- Refresh data with TTL and targeted invalidation, and use a bounded timeout with source fallback.
- Repair the normal price-update path while preserving another product and its cached value.
Who This Course Is For
Complete AWS Foundations for Beginners and basic DynamoDB item operations first. Study the guided labs before the challenge. The application and network are supplied so you can focus on caching rather than unrelated application development.
Each unit starts independently in a browser-based Linux VM with Terminal and AWS View. No personal AWS account or resources from an earlier VM are needed.
Frequently Asked Questions
Does the cache replace the product database?
No. DynamoDB remains authoritative. A cache miss reads the source and stores a reusable copy; expiration must not delete the source item.
Does a successful price update automatically refresh the cache?
Not necessarily. TTL limits the stale window; an application update should invalidate the same key that its read path uses.
What happens if the cache stops answering?
The guided fault exercise demonstrates a bounded timeout and fallback to the source, followed by actual cache recovery. Fallback adds source traffic; production capacity, replication and availability require further study.
