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Metrics

CloudWatch metrics collection with AWS Lambda Powertools integration.

Overview​

Provides a singleton AWS Lambda Powertools Metrics instance for collecting and publishing custom metrics to CloudWatch. The metrics instance leverages Node.js module caching to ensure consistent configuration across your application.

Usage​

import { metrics } from '@leighton-digital/lambda-toolkit';
import { MetricUnits } from '@aws-lambda-powertools/metrics';

// Add custom metrics
metrics.addMetric('UserCreated', MetricUnits.Count, 1);
metrics.addMetric('ProcessingTime', MetricUnits.Milliseconds, 150);
metrics.addMetric('ErrorRate', MetricUnits.Percent, 2.5);

// Within Lambda context
export const handler = withHttpHandler(async ({ event }) => {
  metrics.addMetric('FunctionInvocation', MetricUnits.Count, 1);

  const startTime = Date.now();

  // Your business logic here

  const processingTime = Date.now() - startTime;
  metrics.addMetric('ProcessingDuration', MetricUnits.Milliseconds, processingTime);

  return { statusCode: 200, body: { success: true } };
});

Common Metric Units​

  • MetricUnits.Count - For counting events
  • MetricUnits.Milliseconds - For timing measurements
  • MetricUnits.Percent - For percentage values
  • MetricUnits.Bytes - For memory or data size measurements

Features​

  • CloudWatch Integration: Automatic publishing to CloudWatch Metrics
  • Custom Metrics: Track business-specific measurements
  • Performance Monitoring: Monitor function execution times
  • Error Tracking: Track error rates and counts
  • Singleton Pattern: Consistent configuration across modules