17 Serverless Monitoring Cloudwatch

title: CloudWatch Monitoring for Serverless APIs weight: 27 date: 2026-06-28 lastmod: 2026-06-28 description: Monitor serverless APIs with CloudWatch including custom metrics, structured logging, distributed tracing with X-Ray, CloudWatch Alarms, and dashboard visualization. tags: [api-development, serverless]

CloudWatch monitors Lambda functions with invocations, duration, errors, throttles, and concurrent executions metrics, while CloudWatch Logs capture function output and X-Ray provides distributed tracing across services.

```python
import json
import time
import os
from aws_xray_sdk.core import xray_recorder
from aws_xray_sdk.core import patch_all

patch_all()  # Enable X-Ray tracing

def lambda_handler(event, context):
    # Custom metric
    start_time = time.time()

    try:
        result = process_request(event)
        duration = time.time() - start_time

        # Emit custom metric via CloudWatch Embedded Metric Format
        metric_body = {
            "_aws": {
                "Timestamp": int(time.time() * 1000),
                "CloudWatchMetrics": [
                    {
                        "Namespace": "MyApp",
                        "Dimensions": [["FunctionName", "Stage"]],
                        "Metrics": [{"Name": "ProcessingTime", "Unit": "Milliseconds"}]
                    }
                ],
                "FunctionName": context.function_name,
                "Stage": os.environ.get("STAGE", "dev")
            },
            "ProcessingTime": duration * 1000
        }
        print(json.dumps(metric_body))

        return api_response(200, result)
    except Exception as e:
        print(f"Error: {str(e)}")
        raise

What's Next

Now learn about serverless IAM security in Building Serverless APIs.