Monitoring AWS Lambda Node.js Functionsedit

The Node.js APM Agent can be used with AWS Lambda to monitor the execution of your AWS Lambda functions.

Quick Startedit

To get started with APM for your Node.js AWS Lambda functions follow the steps below.

Prerequisitesedit

You need an APM Server to send APM data to. Follow the APM Quick start if you have not set one up yet. For the best-possible performance, we recommend setting up APM on Elastic Cloud in the same AWS region as your AWS Lambda functions.

Step 1: Select the AWS Region and Architectureedit

Pick the right ARN from this release table for the APM Lambda Extension Layer.

In addition, pick the right ARN from this release table for the APM Agent Layer.

Select the AWS region and architecture of your Lambda function. This documentation will update based on your selections.
region:
architecture:

The selected AWS region and the architecture must match the AWS region and architecture of your AWS Lambda function!

Step 2: Add the APM Layers to your Lambda functionedit

Both the APM Lambda Extension and the Node.js APM Agent are added to your Lambda function as AWS Lambda Layers. Therefore, you need to add the corresponding Layer ARNs (identifiers) to your Lambda function.

To add the layers to your Lambda function through the AWS Management Console:

  1. Navigate to your function in the AWS Management Console
  2. Scroll to the Layers section and click the Add a layer button image of layer configuration section in AWS Console
  3. Choose the Specify an ARN radio button
  4. Copy and paste the following ARNs of the APM Lambda Extension layer and the APM agent layer in the Specify an ARN text input:
    APM Extension layer:
    EXTENSION_ARN
    APM Agent layer:
    AGENT_ARN image of choosing a layer in AWS Console
  5. Click the Add button

Step 3: Configure APM on AWS Lambdaedit

The APM Lambda Extension and the APM Node.js agent are configured through environment variables on the AWS Lambda function.

For the minimal configuration, you will need the APM Server URL to set the destination for APM data and an APM Secret Token. If you prefer to use an APM API key instead of the APM secret token, use the ELASTIC_APM_API_KEY environment variable instead of ELASTIC_APM_SECRET_TOKEN in the following configuration.

To configure APM through the AWS Management Console:

  1. Navigate to your function in the AWS Management Console
  2. Click on the Configuration tab
  3. Click on Environment variables
  4. Add the following required variables:
NODE_OPTIONS                  = -r elastic-apm-node/start # use this exact fixed value
ELASTIC_APM_LAMBDA_APM_SERVER = <YOUR-APM-SERVER-URL>     # this is your APM Server URL
ELASTIC_APM_SECRET_TOKEN      = <YOUR-APM-SECRET-TOKEN>   # this is your APM secret token

Node.js environment variables configuration section in AWS Console

You can optionally fine-tune the Node.js agent or the configuration of the APM Lambda Extension.

That’s it. After following the steps above, you’re ready to go! Your Lambda function invocations should be traced from now on.

Read on to learn more about the features and limitations of the Node.js APM Agent on AWS Lambda Functions.

Features and Caveatsedit

The AWS Lambda as a runtime behaves differently from conventional runtimes. While most APM and monitoring concepts apply to AWS Lambda, there are a few differences and limitations to be aware of.

Performance monitoringedit

Elastic APM automatically measures the performance of your lambda function executions. It records traces for database queries, external HTTP requests, and other slow operations that happen during execution.

By default, the agent will trace the most common modules. To trace other events, you can use custom traces. For information about custom traces, see the Custom Spans section.

Error monitoringedit

By default, the Node.js agent will watch for uncaught exceptions and send them to Elastic APM automatically. But in most cases, errors are not thrown but returned via a callback, caught by a promise, or simply manually created. Those errors will not automatically be sent to Elastic APM. To manually send an error to Elastic APM, simply call apm.captureError() with the error:

var err = new Error('Ups, something broke!')

apm.captureError(err)

For advanced logging of errors, including adding extra metadata to the error, see the API documentation.

Caveatsedit

  • System and custom metrics are not collected for Lambda functions. This is both because most of those are irrelevant and because the interval-based event sending model is not suitable for FaaS environments.