Temporalio.Extensions.Aws.Lambda.OpenTelemetry 1.17.0

AWS Lambda Worker OpenTelemetry Support

This extension adds OpenTelemetry helpers for Temporal workers running inside AWS Lambda.

Add the Temporalio.Extensions.Aws.Lambda.OpenTelemetry package from NuGet. For example, using the dotnet CLI:

dotnet add package Temporalio.Extensions.Aws.Lambda.OpenTelemetry

Quick Start

Call ApplyOpenTelemetryDefaults from the Lambda worker configure callback:

using Amazon.Lambda.Core;
using Temporalio.Common;
using Temporalio.Extensions.Aws.Lambda;
using Temporalio.Extensions.Aws.Lambda.OpenTelemetry;

private static readonly Func<object?, ILambdaContext, Task> WorkerHandler =
    TemporalLambdaWorker.CreateHandler(
        new WorkerDeploymentVersion("payments-worker", "2026-05-27"),
        options =>
        {
            options.ApplyOpenTelemetryDefaults();

            options.WorkerOptions.TaskQueue = "payments";
            options.WorkerOptions.AddWorkflow<PaymentWorkflow>();
            options.WorkerOptions.AddActivity(PaymentActivities.ChargeAsync);
        });

ApplyOpenTelemetryDefaults configures Temporal tracing with TracingInterceptor, creates an OTLP trace exporter and tracer provider, configures Core SDK metrics through a TemporalRuntime, and registers a per-invocation shutdown hook that force-flushes traces before the Lambda invocation ends. It replaces any runtime already set on options.ClientOptions.

Defaults

The OTLP collector endpoint is resolved from LambdaWorkerOpenTelemetryOptions.CollectorEndpoint, then OTEL_EXPORTER_OTLP_ENDPOINT, then http://localhost:4317, which is the endpoint expected by the AWS Distro for OpenTelemetry collector Lambda layer.

The OpenTelemetry service name is resolved from LambdaWorkerOpenTelemetryOptions.ServiceName, then OTEL_SERVICE_NAME, then AWS_LAMBDA_FUNCTION_NAME, then temporal-lambda-worker.

Core SDK metrics export every 10 seconds by default. Set MetricsExportInterval shorter than your Lambda timeout to increase the chance that at least one metrics export happens during each invocation. Core metrics are exported periodically and do not have an explicit per-invocation flush API.

options.ApplyOpenTelemetryDefaults(
    new LambdaWorkerOpenTelemetryOptions
    {
        CollectorEndpoint = "http://localhost:4317",
        ServiceName = "payments-worker",
        MetricsExportInterval = TimeSpan.FromSeconds(5),
    });

AWS Lambda Setup

Attach the ADOT collector Lambda layer and set:

OPENTELEMETRY_COLLECTOR_CONFIG_URI=/var/task/otel-collector-config.yaml

The helper uses AWS X-Ray-compatible trace IDs. It force-flushes traces on every Lambda invocation and disposes the tracer provider during the Lambda shutdown hook.