AWS Lambda - .NET Function Instrumentation

This document covers how to install and configure OpenTelemetry distributed tracing for AWS Lambda functions based on .NET and send the data to Sumo Logic.

To obtain tracing data from AWS Lambda functions developed in .NET, you can use the following components

Provided SDK

OpenTelemetry Lambda SDK for .NET includes tracing APIs to instrument Lambda handlers and is provided on NuGet.

OpenTelemetry Lambda layer

OpenTelemetry Lambda Layer for Collector includes OpenTelemetry Collector for Lambda components. Apply this layer to your Lambda handler that's already been instrumented with the OpenTelemetry Lambda .NET SDK to enable end-to-end tracing.

.NET Lambda layer supports

• .NET 6 SDK or later
• x86_64 and arm64 architectures

Lambda function requirements

You'll need the following:

• .NET 6 SDK or later
• Lambda layers add permissions
• Sumo Logic OTLP/HTTP Source endpoint URL - To send spans from the instrumented Lambda function to Sumo Logic you need an endpoint URL from an existing or new OTLP/HTTP source.

Quick Start

Overview

Prerequisites

• AWS CLI configured with appropriate permissions
• Configure the AWS credential
• .NET 6 SDK
• Sumo Logic OTLP endpoint URL

Configure the lambda function

Navigate to functions in the AWS Lambda Console and open the function you want to instrument.

• Navigate to the Layers section and click Add a layer. Use the following upstream collector lambda layer

  • arn:aws:lambda:<region>:184161586896:layer:opentelemetry-collector-<amd64|arm64>-<version>:1

• In the Choose a layer menu, select Specify an ARN and paste the above ARN ID for your Lambda function

  note

  Lambda layers are a regionalized resource, meaning that they can only be used in the Region in which they are published. Make sure to use the layer in the same region as your Lambda functions.

  By default, OpenTelemetry Collector Lambda layer exports telemetry data to AWS backends. To customize the collector configuration, add a collector.yaml to your function and specify its location via the OPENTELEMETRY_COLLECTOR_CONFIG_URI environment file.

• Configure the collector layer to send data to SumoLogic:

  receivers:
    otlp:
      protocols:
        grpc:
          endpoint: localhost:4317
        http:
          endpoint: localhost:4318
  
  exporters:
    otlphttp:
      endpoint: ${SUMO_LOGIC_OTLP_ENDPOINT}
      headers:
        Content-Type: application/x-protobuf
      encoding: proto
  
  service:
    pipelines:
      traces:
        receivers: [otlp]
        exporters: [otlphttp]

  Once the file has been deployed with a Lambda, configuring the OPENTELEMETRY_COLLECTOR_CONFIG_URI will tell the OpenTelemetry extension where to find the collector configuration:

  aws lambda update-function-configuration --function-name Function --environment Variables={OPENTELEMETRY_COLLECTOR_CONFIG_URI=/var/task/collector.yaml}

• Configure the following environment variables:

  Navigate to the Configuration > Environment variables section and ensure that the following environment variables are setup:

  Variable	Value	Purpose
  OTEL_EXPORTER_OTLP_ENDPOINT	localhost:4318	Collector endpoint
  OTEL_EXPORTER_OTLP_PROTOCOL	http/protobuf	Export protocol
  AWS_LAMBDA_EXEC_WRAPPER	/opt/otel-instrument	Lambda wrapper
  SUMO_LOGIC_OTLP_ENDPOINT	https://your-endpoint.sumologic.net/receiver/v1/otlp/YOUR_TOKEN	Sumo Logic endpoint
  OPENTELEMETRY_COLLECTOR_CONFIG_URI	/var/task/collector.yaml	Collector configuration

Any other environment variables like OTEL_RESOURCE_ATTRIBUTES or OTEL_SERVICE_NAME could also be configured.

Your function should be successfully instrumented. Invoke the function and find your traces in the Sumo Logic Tracing screen

References

• OpenTelemetry Lambda Layer Documentation
• Sumo Logic OTLP Integration