Merge pull request #110776 from MS-jgol/correlation-doc

modified telemetry correlation for Java

Author: PRMerger6

articles/azure-monitor/app/correlation.md

@@ -125,6 +125,11 @@ public void ConfigureServices(IServiceCollection services)
 
 ### Enable W3C distributed tracing support for Java apps
 
+#### Java 3.0 agent
+
+  Java 3.0 agent supports W3C out of the box and no additional configuration is needed. 
+
+#### Java SDK
 - **Incoming configuration**
 
   - For Java EE apps, add the following to the `<TelemetryModules>` tag in ApplicationInsights.xml:
@@ -316,18 +321,33 @@ There's a new HTTP module, [Microsoft.AspNet.TelemetryCorrelation](https://www.n
 The Application Insights SDK, starting with version 2.4.0-beta1, uses `DiagnosticSource` and `Activity` to collect telemetry and associate it with the current activity.
 
 <a name="java-correlation"></a>
-## Telemetry correlation in the Java
+## Telemetry correlation in Java
 
-[Application Insights Java agent](https://docs.microsoft.com/azure/azure-monitor/app/java-in-process-agent) as well as [Java SDK](../../azure-monitor/app/java-get-started.md) version 2.0.0 or later supports automatic correlation of telemetry. It automatically populates `operation_id` for all telemetry (like traces, exceptions, and custom events) issued within the scope of a request. It also propagates the correlation headers (described earlier) for service-to-service calls via HTTP, if the [Java SDK agent](../../azure-monitor/app/java-agent.md) is configured.
+[Java agent](https://docs.microsoft.com/azure/azure-monitor/app/java-in-process-agent) as well as [Java SDK](../../azure-monitor/app/java-get-started.md) version 2.0.0 or later supports automatic correlation of telemetry. It automatically populates `operation_id` for all telemetry (like traces, exceptions, and custom events) issued within the scope of a request. It also propagates the correlation headers (described earlier) for service-to-service calls via HTTP, if the [Java SDK agent](../../azure-monitor/app/java-agent.md) is configured.
 
 > [!NOTE]
 > Application Insights Java agent auto-collects requests and dependencies for JMS, Kafka, Netty/Webflux, and more. For Java SDK only calls made via Apache HttpClient are supported for the correlation feature. Automatic context propagation across messaging technologies (like Kafka, RabbitMQ, and Azure Service Bus) isn't supported in the SDK. 
 
-<a name="java-role-name"></a>
-## Role name
+> [!NOTE]
+> To collect custom telemetry you need to instrument the application with Java 2.6 SDK. 
+
+### Role names
 
 You might want to customize the way component names are displayed in the [Application Map](../../azure-monitor/app/app-map.md). To do so, you can manually set the `cloud_RoleName` by taking one of the following actions:
 
+- For Application Insights Java agent 3.0, set the cloud role name as follows:
+
+    ```json
+    {
+      "instrumentationSettings": {
+        "preview": {
+          "roleName": "my cloud role name"
+        }
+      }
+    }
+    ```
+    You can also set the cloud role name using the environment variable `APPLICATIONINSIGHTS_ROLE_NAME`.
+
 - With Application Insights Java SDK 2.5.0 and later, you can specify the `cloud_RoleName`
   by adding `<RoleName>` to your ApplicationInsights.xml file: