Keep each customer’s updates in order — SQS and FIFO queues

Your goal

Send two updates in one message group and read their order.

Why this matters

Related updates may need to be handled in their sent order. You will send two messages in one group and compare their returned order. Real workers still need safe retry handling.

Words you will use

FIFO means first in, first out. A message group is an ordered lane. A deduplication ID helps identify repeated sends within the queue’s deduplication window.

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 an ordered queue

Create a queue whose name ends in .fifo, with FIFO and content-based deduplication enabled. Ordering applies within a message group, not across all customers everywhere.

2. Send two updates for the same customer

Send first-update, then your message, using the same customer-1 message group and distinct deduplication IDs. Keeping related updates in one group gives them an order.

Practice message: Type a short message that you can recognize in the API result. Suggested practice value: Hello from my lab.

3. Read and compare their order

Receive the two messages together and check which came first. They remain visible for the final verification. Real consumers still need safe handling for retries and duplicate work.

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.