# Instrument a Java container for Datadog

This guide shows you how to instrument Java applications running in Amazon ECS containers. OpenTelemetry Collector is configured to collect the resulting logs, metrics, and traces.

## Things to consider

<!-- prettier-ignore-start -->
!!! tip "Recommended practice"
    Enable auto-instrumentation to automatically capture useful telemetry from HTTP requests, database queries, external service calls, and application logs. You don't need to change any code in your app.
<!-- prettier-ignore-end -->

## Before you begin

Make sure you have:

- Completed the [getting started guide to set up basic Datadog integration](../initial-setup-of-your-aws-environment/set-up-datadog.md).
- A Java application deployed using the `app` template.

## Step 1: Enable telemetry collection and auto-instrumentation

Auto-instrumentation automatically captures logs, metrics, and traces from your Java app. You don't need to change any code in your app.

1. Update to the newest version of the `app` template for the application you want to instrument.

1. Edit your `package-config.yml` file to enable telemetry collection:

   ```yml
   TelemetryCollection:
     Enable: true
     AutoInstrumentation:
       Enable: true # Disable this if you're already bundling the Java Agent with your application
       Runtime: java # This is the only supported runtime for auto-instrumentation
   ```

1. Apply the configuration:

   ```sh
   ok pkg install
   ```

1. Apply the Terraform configuration:

   ```sh
   terraform plan
   terraform apply
   ```

## Step 2: Add manual instrumentation (optional)

Auto-instrumentation provides basic telemetry, but custom business metrics need manual instrumentation with the OpenTelemetry SDK. Add the API dependency and use `@WithSpan` annotations or the API directly.

For detailed instructions on manual instrumentation, see the [OpenTelemetry Java documentation](https://opentelemetry.io/docs/instrumentation/java/manual/).

## Step 3: Verify instrumentation

Check Datadog for incoming traces, metrics, and logs. Use the `env` and `service` tags to filter the results. For example:

```text
env:pirates-dev service:too-tikki`.
```

## Next steps

With an instrumented application you can now [customize OTel configuration](customize-otel-configuration.md) to more granularly control which telemetry gets sent to Datadog from your application.