Get started with Application Insights in a Java web project

  • 7 minutes to read

Application Insights is an extensible analytics service for web developers that helps you understand the performance and usage of your live application. Use it to automatically instrument request, track dependencies, and collect performance counters, diagnose performance issues and exceptions, and write code to track what users do with your app.

Screenshot of overview sample data

Application Insights supports Java apps running on Linux, Unix, or Windows.

You need:

1. Get an Application Insights instrumentation key

  1. Sign in to the Microsoft Azure portal.

  2. Create an Application Insights resource. Set the application type to Java web application.

  3. Find the instrumentation key of the new resource. You'll need to paste this key into your code project shortly.

    In the new resource overview, click Properties and copy the Instrumentation Key

2. Add the Application Insights SDK for Java to your project

Choose the appropriate way for your project.

If you're using Maven...

If your project is already set up to use Maven for build, merge the following code to your pom.xml file.

Then, refresh the project dependencies to get the binaries downloaded.

    <dependencies>
      <dependency>
        <groupId>com.microsoft.azure</groupId>
        <artifactId>applicationinsights-web-auto</artifactId>
        <!-- or applicationinsights-web for manual web filter registration -->
        <!-- or applicationinsights-core for bare API -->
        <version>2.5.0</version>
      </dependency>
    </dependencies>

If you're using Gradle...

If your project is already set up to use Gradle for build, merge the following code to your build.gradle file.

Then refresh the project dependencies to get the binaries downloaded.

    dependencies {
      compile group: 'com.microsoft.azure', name: 'applicationinsights-web-auto', version: '2.5.0'
      // or applicationinsights-web for manual web filter registration
      // or applicationinsights-core for bare API
    }

Otherwise, if you are manually managing dependencies ...

Download the latest version and copy the necessary files into your project, replacing any previous versions.

Questions...

  • What's the relationship between the -web-auto, -web and -core components?

    • applicationinsights-web-auto gives you metrics that track HTTP servlet request counts and response times, by automatically registering the Application Insights servlet filter at runtime.
    • applicationinsights-web also gives you metrics that track HTTP servlet request counts and response times, but requires manual registration of the Application Insights servlet filter in your application.
    • applicationinsights-core gives you just the bare API, for example, if your application is not servlet-based.

  • How should I update the SDK to the latest version?

    • If you are using Gradle or Maven...
      • Update your build file to specify the latest version.
    • If you are manually managing dependencies...

3. Add an ApplicationInsights.xml file

Add ApplicationInsights.xml to the resources folder in your project, or make sure it is added to your project’s deployment class path. Copy the following XML into it.

Substitute the instrumentation key that you got from the Azure portal.

<?xml version="1.0" encoding="utf-8"?>
<ApplicationInsights xmlns="http://schemas.microsoft.com/ApplicationInsights/2013/Settings" schemaVersion="2014-05-30">

   <!-- The key from the portal: -->
   <InstrumentationKey>** Your instrumentation key **</InstrumentationKey>

   <!-- HTTP request component (not required for bare API) -->
   <TelemetryModules>
      <Add type="com.microsoft.applicationinsights.web.extensibility.modules.WebRequestTrackingTelemetryModule"/>
      <Add type="com.microsoft.applicationinsights.web.extensibility.modules.WebSessionTrackingTelemetryModule"/>
      <Add type="com.microsoft.applicationinsights.web.extensibility.modules.WebUserTrackingTelemetryModule"/>
   </TelemetryModules>

   <!-- Events correlation (not required for bare API) -->
   <!-- These initializers add context data to each event -->
   <TelemetryInitializers>
      <Add type="com.microsoft.applicationinsights.web.extensibility.initializers.WebOperationIdTelemetryInitializer"/>
      <Add type="com.microsoft.applicationinsights.web.extensibility.initializers.WebOperationNameTelemetryInitializer"/>
      <Add type="com.microsoft.applicationinsights.web.extensibility.initializers.WebSessionTelemetryInitializer"/>
      <Add type="com.microsoft.applicationinsights.web.extensibility.initializers.WebUserTelemetryInitializer"/>
      <Add type="com.microsoft.applicationinsights.web.extensibility.initializers.WebUserAgentTelemetryInitializer"/>
   </TelemetryInitializers>

</ApplicationInsights>

Optionally, the configuration file can reside in any location accessible to your application. The system property -Dapplicationinsights.configurationDirectory specifies the directory that contains ApplicationInsights.xml. For example, a configuration file located at E:\myconfigs\appinsights\ApplicationInsights.xml would be configured with the property -Dapplicationinsights.configurationDirectory="E:\myconfigs\appinsights".

  • The instrumentation key is sent along with every item of telemetry and tells Application Insights to display it in your resource.
  • The HTTP Request component is optional. It automatically sends telemetry about requests and response times to the portal.
  • Event correlation is an addition to the HTTP request component. It assigns an identifier to each request received by the server, and adds this identifier as a property to every item of telemetry as the property 'Operation.Id'. It allows you to correlate the telemetry associated with each request by setting a filter in diagnostic search.

Alternative ways to set the instrumentation key

Application Insights SDK looks for the key in this order:

  1. System property: -DAPPINSIGHTS_INSTRUMENTATIONKEY=your_ikey
  2. Environment variable: APPINSIGHTS_INSTRUMENTATIONKEY
  3. Configuration file: ApplicationInsights.xml

You can also set it in code:

    String instrumentationKey = "00000000-0000-0000-0000-000000000000";

    if (instrumentationKey != null)
    {
        TelemetryConfiguration.getActive().setInstrumentationKey(instrumentationKey);
    }

4. Add agent

Install the Java Agent to capture outgoing HTTP calls, JDBC queries, application logging, and better operation naming.

5. Run your application

Either run it in debug mode on your development machine, or publish to your server.

6. View your telemetry in Application Insights

Return to your Application Insights resource in Microsoft Azure portal.

HTTP requests data appears on the overview blade. (If it isn't there, wait a few seconds and then click Refresh.)

Screenshot of overview sample data

Learn more about metrics.

Click through any chart to see more detailed aggregated metrics.

Application Insights failures pane with charts

Instance data

Click through a specific request type to see individual instances.

Drill into a specific sample view

Analytics: Powerful query language

As you accumulate more data, you can run queries both to aggregate data and to find individual instances. Analytics is a powerful tool for both for understanding performance and usage, and for diagnostic purposes.

Example of Analytics

7. Install your app on the server

Now publish your app to the server, let people use it, and watch the telemetry show up on the portal.

  • Make sure your firewall allows your application to send telemetry to these ports:

    • dc.services.visualstudio.com:443
    • f5.services.visualstudio.com:443

  • If outgoing traffic must be routed through a firewall, define system properties http.proxyHost and http.proxyPort.

  • On Windows servers, install:

Azure App Service config (Spring Boot)

Spring Boot apps running on Windows require additional configuration to run on Azure App Services. Modify web.config and add the following:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <handlers>
            <add name="httpPlatformHandler" path="*" verb="*" modules="httpPlatformHandler" resourceType="Unspecified"/>
        </handlers>
        <httpPlatform processPath="%JAVA_HOME%\bin\java.exe" arguments="-Djava.net.preferIPv4Stack=true -Dserver.port=%HTTP_PLATFORM_PORT% -jar &quot;%HOME%\site\wwwroot\AzureWebAppExample-0.0.1-SNAPSHOT.jar&quot;">
        </httpPlatform>
    </system.webServer>
</configuration>

Exceptions and request failures

Unhandled exceptions and request failures are automatically collected by the Application Insights web filter.

To collect data on other exceptions, you can insert calls to trackException() in your code.

Monitor method calls and external dependencies

Install the Java Agent to log specified internal methods and calls made through JDBC, with timing data.

And for automatic operation naming.

W3C distributed tracing

The Application Insights Java SDK now supports W3C distributed tracing.

The incoming SDK configuration is explained further in our article on correlation.

Outgoing SDK configuration is defined in the AI-Agent.xml file.

Performance counters

Open Investigate, Metrics, to see a range of performance counters.

Screenshot of metrics pane with process private bytes selected

Customize performance counter collection

To disable collection of the standard set of performance counters, add the following code under the root node of the ApplicationInsights.xml file:

    <PerformanceCounters>
       <UseBuiltIn>False</UseBuiltIn>
    </PerformanceCounters>

Collect additional performance counters

You can specify additional performance counters to be collected.

JMX counters (exposed by the Java Virtual Machine)

    <PerformanceCounters>
      <Jmx>
        <Add objectName="java.lang:type=ClassLoading" attribute="TotalLoadedClassCount" displayName="Loaded Class Count"/>
        <Add objectName="java.lang:type=Memory" attribute="HeapMemoryUsage.used" displayName="Heap Memory Usage-used" type="composite"/>
      </Jmx>
    </PerformanceCounters>
  • displayName – The name displayed in the Application Insights portal.
  • objectName – The JMX object name.
  • attribute – The attribute of the JMX object name to fetch
  • type (optional) - The type of JMX object’s attribute:
    • Default: a simple type such as int or long.
    • composite: the perf counter data is in the format of 'Attribute.Data'
    • tabular: the perf counter data is in the format of a table row

Windows performance counters

Each Windows performance counter is a member of a category (in the same way that a field is a member of a class). Categories can either be global, or can have numbered or named instances.

    <PerformanceCounters>
      <Windows>
        <Add displayName="Process User Time" categoryName="Process" counterName="%User Time" instanceName="__SELF__" />
        <Add displayName="Bytes Printed per Second" categoryName="Print Queue" counterName="Bytes Printed/sec" instanceName="Fax" />
      </Windows>
    </PerformanceCounters>
  • displayName – The name displayed in the Application Insights portal.
  • categoryName – The performance counter category (performance object) with which this performance counter is associated.
  • counterName – The name of the performance counter.
  • instanceName – The name of the performance counter category instance, or an empty string (""), if the category contains a single instance. If the categoryName is Process, and the performance counter you'd like to collect is from the current JVM process on which your app is running, specify "__SELF__".

Unix performance counters

Get user and session data

OK, you're sending telemetry from your web server. Now to get the full 360-degree view of your application, you can add more monitoring:

Send your own telemetry

Now that you've installed the SDK, you can use the API to send your own telemetry.

Availability web tests

Application Insights can test your website at regular intervals to check that it's up and responding well.

Learn more about how to set up availability web tests.

Questions? Problems?

Troubleshooting Java

Next steps