Remember answers you use often — ElastiCache

Your goal

Create a Redis parameter group and configure how a full cache makes room.

Why this matters

A cache needs a rule for what to remove when memory fills. You will create a parameter group and choose its eviction policy. This prepares configuration without claiming that a cache server or app is running.

Words you will use

A cache is a fast place for reusable data. A cache hit finds a saved answer; a miss does not. Invalidation removes a saved answer that should no longer be used.

How to proceed

Start a fresh emulator, read each numbered step, and enter the practice settings shown. Run the action, inspect its API receipt, then continue. Finish lab checks the emulator state again before saving your progress.

1. Create a cache parameter group

Create a Redis 7 parameter group for your practice app. Parameter groups hold cache settings. This lab configures the policy; it does not run a Redis server.

2. Choose an eviction policy

Save allkeys-lru as the memory policy. It allows least-recently-used keys to be removed when room is needed. An app must be able to handle a missing cached value.

3. Read the cache parameters

Describe the group and its parameters. Find maxmemory-policy and verify the saved value. Cache configuration and application correctness both matter.

Practice, then check your understanding

Perform the actions yourself and inspect the returned state. Errors keep your settings so you can retry. Starting another lab clears the previous live environment. Earned XP is kept, and signed-in achievements sync to your account. Replay does not award duplicate XP.

Read the official AWS documentation for service behavior and production details.