Give a failed function another chance — Lambda and Retries

Your goal

Configure asynchronous retry limits and inspect the stored policy.

Why this matters

Background function calls can be retried after a failure. You will choose an asynchronous retry limit and inspect the saved policy. Applications still need to handle repeated work safely.

Words you will use

Asynchronous means the caller does not wait for the function result. A retry repeats an attempt. A failure destination receives details when processing cannot finish.

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 your practice function

Create a Lambda function using the site’s fixed practice handler. Wait for its state to become Active. Your function has its own name and role in this emulator.

2. Bound asynchronous retries

Choose zero, one, or two retries and save a maximum event age of 60 seconds. These settings apply to the function’s asynchronous invocation configuration, not every event-source retry mechanism.

Maximum retry attempts: Choose 0, 1, or 2 retries. The lab reads the saved policy; it does not simulate delayed delivery. Suggested practice value: 1.

3. Read the function setting

Retrieve the setting from the emulator and compare it with your input. The returned state is the evidence used to complete this lab.

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.