Monitor AWS Lambda Cron Jobs with CronRabbit

The Problem

AWS Lambda functions triggered by CloudWatch Events can timeout, cold-start fail, or exceed concurrency limits without any notification beyond CloudWatch logs.

The Solution

Add an HTTP call to CronRabbit at the end of your Lambda handler. If the function fails to complete, CronRabbit alerts you within the grace period.

Why CloudWatch Alone Isn't Enough

CloudWatch alarms can monitor error rates, but they require complex metric math to detect 'missing executions'. CronRabbit is purpose-built for this: no ping = alert.

Lambda Integration

Add a simple fetch/requests call as the last line of your handler. Keep the timeout short (<5 seconds) to avoid adding lambda cost.

Code Examples

Lambda handler with monitoring

Python

import urllib.request

PING = "https://ping.cronrabbit.com/your-id"

def lambda_handler(event, context):
    urllib.request.urlopen(f"{PING}/start", timeout=5)
    try:
        result = process_batch(event)
        urllib.request.urlopen(PING, timeout=5)
        return result
    except Exception:
        urllib.request.urlopen(f"{PING}/fail", timeout=5)
        raise

Related Guides

AWS

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