@aws-lambda-powertools/metrics

What is @aws-lambda-powertools/metrics?

@aws-lambda-powertools/metrics is an npm package designed to simplify the creation and management of custom metrics in AWS Lambda functions. It provides utilities to easily capture and publish metrics to Amazon CloudWatch, enabling better observability and monitoring of serverless applications.

What are @aws-lambda-powertools/metrics's main functionalities?

Creating Custom Metrics

This feature allows you to create custom metrics and publish them to CloudWatch. The code sample demonstrates how to add metrics for successful invocations and processing time, and then publish them.

const { Metrics, MetricUnits } = require('@aws-lambda-powertools/metrics');

const metrics = new Metrics();

exports.handler = async (event) => {
  metrics.addMetric('SuccessfulInvocations', MetricUnits.Count, 1);
  metrics.addMetric('ProcessingTime', MetricUnits.Milliseconds, 200);
  await metrics.publishStoredMetrics();
  return { statusCode: 200, body: 'Metrics published' };
};

Namespace and Dimensions

This feature allows you to set a namespace and dimensions for your metrics, which helps in organizing and filtering them in CloudWatch. The code sample shows how to set a namespace and dimensions for a payment service.

const { Metrics, MetricUnits } = require('@aws-lambda-powertools/metrics');

const metrics = new Metrics({ namespace: 'MyApp', dimensions: { Service: 'Payment' } });

exports.handler = async (event) => {
  metrics.addMetric('PaymentSuccess', MetricUnits.Count, 1);
  await metrics.publishStoredMetrics();
  return { statusCode: 200, body: 'Payment metrics published' };
};

Automatic Cold Start Metric

This feature automatically captures a cold start metric, which is useful for understanding the performance impact of cold starts in your Lambda functions. The code sample demonstrates how to enable this feature.

const { Metrics, MetricUnits } = require('@aws-lambda-powertools/metrics');

const metrics = new Metrics({ captureColdStartMetric: true });

exports.handler = async (event) => {
  metrics.addMetric('HandlerInvoked', MetricUnits.Count, 1);
  await metrics.publishStoredMetrics();
  return { statusCode: 200, body: 'Cold start metric captured' };
};

Other packages similar to @aws-lambda-powertools/metrics

aws-sdk

The aws-sdk package is the official AWS SDK for JavaScript, which includes support for CloudWatch metrics. However, it requires more boilerplate code to achieve the same functionality as @aws-lambda-powertools/metrics. It is more general-purpose and not specifically tailored for Lambda functions.

cloudwatch-metrics

The cloudwatch-metrics package is a lightweight library for publishing metrics to CloudWatch. It provides a simpler interface compared to the aws-sdk but lacks some of the advanced features and integrations offered by @aws-lambda-powertools/metrics, such as automatic cold start metrics.

README

Powertools for AWS Lambda (TypeScript)

Powertools for AWS Lambda (TypeScript) is a developer toolkit to implement Serverless best practices and increase developer velocity.

You can use the library in both TypeScript and JavaScript code bases.

Also available in Python, Java, and .NET.

Documentation | npm | Roadmap | Examples | Serverless TypeScript Demo

Table of contents

• Features
• Getting started
  • Installation
  • Examples
  • Serverless TypeScript Demo application
• Contribute
• Roadmap
• Connect
• How to support Powertools for AWS Lambda (TypeScript)?
  • Becoming a reference customer
  • Sharing your work
  • Using Lambda Layer
• Credits
• License

Features

• Tracer - Utilities to trace Lambda function handlers, and both synchronous and asynchronous functions
• Logger - Structured logging made easier, and a middleware to enrich log items with key details of the Lambda context
• Metrics - Custom Metrics created asynchronously via CloudWatch Embedded Metric Format (EMF)
• Parameters - High-level functions to retrieve one or more parameters from AWS SSM, Secrets Manager, AppConfig, and DynamoDB

Getting started

Find the complete project's documentation here.

Installation

The Powertools for AWS Lambda (TypeScript) utilities follow a modular approach, similar to the official AWS SDK v3 for JavaScript.
Each TypeScript utility is installed as standalone NPM package.

Install all three core utilities at once with this single command:

npm install @aws-lambda-powertools/logger @aws-lambda-powertools/tracer @aws-lambda-powertools/metrics

Or refer to the installation guide of each utility:

👉 Installation guide for the Tracer utility

👉 Installation guide for the Logger utility

👉 Installation guide for the Metrics utility

👉 Installation guide for the Parameters utility

Examples

• CDK
• SAM

Serverless TypeScript Demo application

The Serverless TypeScript Demo shows how to use Powertools for AWS Lambda (TypeScript).
You can find instructions on how to deploy and load test this application in the repository.

Contribute

If you are interested in contributing to this project, please refer to our Contributing Guidelines.

Roadmap

The roadmap of Powertools for AWS Lambda (TypeScript) is driven by customers’ demand.
Help us prioritize upcoming functionalities or utilities by upvoting existing RFCs and feature requests, or creating new ones, in this GitHub repository.

Connect

• Powertools for AWS Lambda on Discord: #typescript - Invite link
• Email: [e-mail]

How to support Powertools for AWS Lambda (TypeScript)?

Becoming a reference customer

Knowing which companies are using this library is important to help prioritize the project internally. If your company is using Powertools for AWS Lambda (TypeScript), you can request to have your name and logo added to the README file by raising a Support Powertools for AWS Lambda (TypeScript) (become a reference) issue.

The following companies, among others, use Powertools:

• Hashnode
• Trek10
• Elva
• globaldatanet
• Bailey Nelson
• Perfect Post
• Sennder
• Certible
• tecRacer GmbH & Co. KG

Sharing your work

Share what you did with Powertools for AWS Lambda (TypeScript) 💞💞. Blog post, workshops, presentation, sample apps and others. Check out what the community has already shared about Powertools for AWS Lambda (TypeScript) here.

Using Lambda Layer

This helps us understand who uses Powertools for AWS Lambda (TypeScript) in a non-intrusive way, and helps us gain future investments for other Powertools for AWS Lambda languages. When using Layers, you can add Powertools for AWS Lambda (TypeScript) as a dev dependency (or as part of your virtual env) to not impact the development process.

Credits

Credits for the Powertools for AWS Lambda (TypeScript) idea go to DAZN and their DAZN Lambda Powertools.

License

This library is licensed under the MIT-0 License. See the LICENSE file.

Changelog

1.14.0 (2023-09-29)

Features

• idempotency: add idempotency decorator (#1723) (d138673)
• layers: add arm64 to integration test matrix (#1720) (61ad5ac)
• tracer: add try/catch logic to decorator and middleware close (#1716) (be16b59)