AWS Lambda and IoT Applications
Instruction: Explain how AWS Lambda can be utilized in Internet of Things (IoT) applications.
Updated
Official answer
A common path is device telemetry → AWS IoT Core → an IoT rule → Lambda → a database or notification service. The rule filters or transforms MQTT messages; its Lambda action invokes the function asynchronously. Grant the IoT service invocation permission scoped to the intended rule and account.
For a temperature sensor, validate the authenticated device's allowed topic and the payload's device ID, timestamp, units and range. Do not trust a device ID supplied in a message without relating it to the authorized publishing identity. Use an event ID or device sequence number to handle duplicates, and define how late readings affect alerts.
Lambda can enrich a reading, update a durable aggregate or request an alert. Separate a requested device action from confirmation that the device received and applied it. Device shadows can represent desired and reported state, but connectivity loss and stale state still need handling.
Configure rule-action error handling and Lambda asynchronous failure retention separately, monitor ingestion-to-action latency, and test offline devices, malformed readings and replay. Execution Duration excludes some delivery and queueing time.
Keep safety-critical immediate control on an appropriate local device or controller when cloud availability or latency cannot meet the requirement. Lambda and IoT Core support cloud workflows; they do not guarantee a hard real-time response.