Monitor AWS Lambda Using OpenTelemetry Instrumentation

Splunk AppDynamics recommends using the open-source OpenTelemetry instrumentation layer and environment variables to communicate with the Cisco AppDynamics Distribution of OpenTelemetry Collector.

To do so, use the following steps on Lambda Auto-Instrumentation:

1. If you have an open source Java layer already installed, remove the layer from your Lambda. Otherwise, continue to Step 2.
2. Fetch the Splunk AppDynamics Layer .zip file from Artifactory. Create a layer according to Creating and deleting layers in Lambda. 

3. Configure your environment variables.
   In addition to the listed environment variables, add the following environment variables in the Lambda setup:

   Environment Variable	Environment Variable Value	Required	Description
   OTEL_EXPORTER_OTLP_ENDPOINT	http://<collector_endpoint>:<port>	Yes	Defines the URL to the Cisco AppDynamics Distribution of OpenTelemetry Collector.
   AWS_LAMBDA_EXEC_WRAPPER	/opt/appd-otel-handler	Yes	Runs an Splunk AppDynamics script on Lambda startup.
   OTEL_SERVICE_NAME	<your desired service name>	No	The desired service name for your Lambda.

   

   The OpenTelemetry spec already defines these environment variables, but you must use Splunk AppDynamics's instead.

Splunk AppDynamics recommends using the open-source OpenTelemetry instrumentation layer and environment variables to communicate with the Cisco AppDynamics Distribution of OpenTelemetry Collector.

To do so, use the following steps on Lambda Auto-Instrumentation:

1. Add the ARN of Instrumentation Lambda Layer.
   For this deployment, you only need to add and configure the instrumentation layer. Do not add, configure, or enable tracing for the Collector layer as mentioned in the OpenTelemetry documentation.
2. Fetch the Splunk AppDynamics Layer .zip file from Artifactory. Create a layer according to Creating and deleting layers in Lambda. 

3. Configure your environment variables.
   In addition to the listed environment variables, add the following environment variables in the Lambda setup:

   Environment Variable	Environment Variable Value	Required	Description
   OTEL_EXPORTER_OTLP_ENDPOINT	http://<collector_endpoint>:<port>	Yes	Defines the URL to the Cisco AppDynamics Distribution of OpenTelemetry Collector.
   OTEL_LAMBDA_DISABLE_AWS_CONTEXT_PROPAGATION	true	Yes	Defines if AWS context propagation is disabled.
   AWS_LAMBDA_EXEC_WRAPPER	/opt/appd-otel-handler	Yes	Runs an Splunk AppDynamics script on Lambda startup.
   OTEL_SERVICE_NAME	<your desired service name>	No	The desired service name for your Lambda.

   

   The OpenTelemetry spec already defines these environment variables, but you must use Splunk AppDynamics's instead.

Splunk AppDynamics recommends using the open-source OpenTelemetry instrumentation layer and environment variables to communicate with the Cisco AppDynamics Distribution of OpenTelemetry Collector.

To do so, use the following steps on Lambda Auto-Instrumentation:

1. Add the ARN of Instrumentation Lambda Layer
   For this deployment, you only need to add and configure the instrumentation layer. Do not add, configure, or enable tracing for the Collector layer as mentioned in the OpenTelemetry documentation.
2. Fetch the Splunk AppDynamics Layer .zip file from Artifactory. Create a layer according to Creating and deleting layers in Lambda. 

3. Configure your environment variables.
   In addition to the listed environment variables, add the following environment variables in the Lambda setup:

   Environment Variable	Environment Variable Value	Required	Description
   OTEL_EXPORTER_OTLP_ENDPOINT	http://<collector_endpoint>:<port>	Yes	Defines the URL to the Cisco AppDynamics Distribution of OpenTelemetry Collector.
   OTEL_LAMBDA_DISABLE_AWS_CONTEXT_PROPAGATION	true	Yes	Defines if AWS context propagation is disabled.
   AWS_LAMBDA_EXEC_WRAPPER	/opt/appd-otel-handler	Yes	Runs an Splunk AppDynamics script on Lambda startup.
   OTEL_SERVICE_NAME	<your desired service name>	No	The desired service name for your Lambda.

   

   The OpenTelemetry spec already defines these environment variables, but you must use Splunk AppDynamics's instead.

Use the following steps to manually instrument the Lambda handler. For other instrumentations, such as http, you need to include the corresponding library instrumentation from the instrumentation project and modify your code to initialize it in your function.

The .NET manual instrumentation is through a NuGet package (dependency) rather than a separate ZIP artifact.

1. Install the AppDynamics Lambda .NET package to your Lambda function:

   dotnet add package AppDynamics.OpenTelemetry.Instrumentation.AWSLambda

   CODE

   OR add the following dependency to your .csproj  file:
   

   <PackageReference Include="AppDynamics.OpenTelemetry.Instrumentation.AWSLambda" Version="*" />

   CODE

   
   

2. Initialize the OpenTelemetry tracer and add a call to AddAWSLambdaConfigurations() from  TracerProvider.

   _tracerProvider = Sdk.CreateTracerProviderBuilder()    
               // add other instrumentations
               .AddAWSInstrumentation()
               .AddOtlpExporter()
               .AddAWSLambdaConfigurations()
               .Build();

   CODE

3. Create a wrapper function with the same signature as the original Lambda function. Call AppDynamicsLambdaWrapper.Trace() API and pass _tracerProvider, the original Lambda function, and its inputs as parameters. Set the wrapper function TracingFunctionHandler as the Lambda handler input.
   

   public Task TracingFunctionHandler(SQSEvent input, ILambdaContext context)
       => AppDynamicsLambdaWrapper.Trace(_tracerProvider, OriginalFunctionHandler, input, context);
   
   public Task OriginalFunctionHandler(SQSEvent input, ILambdaContext context)
   {
       // Lambda function logic
       return Task.CompletedTask;
   }

   CODE

   
   

4. Configure your environment variables. Add the following environment variables in the Lambda setup:

   Environment Variable	Environment Variable Value	Required	Description
   OTEL_EXPORTER_OTLP_ENDPOINT	http://<collector_endpoint>:<port>	Yes	Defines the URL to the Cisco AppDynamics Distribution of OpenTelemetry Collector.
   OTEL_LAMBDA_DISABLE_AWS_CONTEXT_PROPAGATION	true	Yes	Defines if AWS context propagation is disabled.