Send the function only matching work — Lambda and Event filtering

Your goal

Save a queue event filter and inspect which message kind it matches.

Why this matters

A queue consumer may need only certain kinds of messages. You will save a filter on a disabled event source mapping and inspect the exact rule. Keeping it disabled makes the configuration boundary clear.

Words you will use

An event source mapping connects a queue or stream to Lambda. A filter matches selected records. Unmatched SQS messages are removed by Lambda, so the filter needs care.

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 function and source queue

Create the practice Lambda function and an SQS queue. Read the queue ARN so the event source mapping can refer to the exact queue in this sandbox.

2. Save a disabled mapping with a filter

Choose the message kind to match, then create a disabled mapping with that body filter. It stays disabled so this configuration exercise cannot consume messages while you inspect it.

Message kind: Select the body.kind value the filter should match. Suggested practice value: upload.

3. Read the mapping

Retrieve the mapping and inspect FilterCriteria. Lambda removes unmatched SQS messages when a mapping processes them; a filter is not a separate inbox that preserves all excluded 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.