Java

This guide walks you through setting up Application Performance Monitoring (APM) on a Go application. You can also check the Installation page in your Middleware Account for these instructions. To test the Java APM feature, use this example code.

Prerequisites

Before you begin, ensure you have the following:

Installation steps

Step 1: Download the Middleware.io Java Agent

Download the latest Middleware instrumentation JAR file from the Github Release Page.

Step 2: Place the Agent JAR file

Place the downloaded middleware-javaagent.jar file in a location accessible by your Java application. A common practice is to create a dedicated directory for agents, e.g., /opt/middleware-agent/.

sudo mkdir -p /opt/middleware-agent
sudo mv middleware-javaagent.jar /opt/middleware-agent/

Step 3: Configure the Java application to load the agent

To enable the Middleware.io agent, you need to add a JVM argument to your Java application's startup script. This argument tells the JVM to load the agent before your application starts.

Common Scenarios:

Step 4: Restart your application

After making the necessary changes to your application's startup configuration, you must restart your Java application for the Middleware.io agent to be loaded and begin monitoring.

Step 5: Verify Installation

After restarting your application, follow these steps to confirm the Middleware.io agent is running and reporting data:

1. Check Application Logs:

   • Examine your application's standard output or log files (e.g., catalina.out for Tomcat, or your application's specific log file).
   • Look for messages indicating that the Middleware.io agent has started successfully. These messages often begin with [Middleware Agent] or similar.
   • You should see messages like:

     [Middleware Agent] Agent started successfully.
     [Middleware Agent] Connected to Middleware.io platform.
     [Middleware Agent] Sending data for application: YourJavaApplication, environment: production

     

   • If you see errors, refer to the Troubleshooting Guide.

2. Generate Some Application Traffic:

   • Interact with your Java application to generate some traffic (e.g., make a few HTTP requests, trigger some database calls). This ensures there's data for the agent to collect and send.

3. Check your Middleware.io dashboard:

   • Log in to your Middleware.io dashboard.
   • Navigate to the APM section or your list of monitored applications.
   • Within a few minutes, you should see your application listed (using the name configured by mw.agent.application_name) and metrics (like CPU, memory, request rates) should start appearing.

If you don't see your application or data after these steps, check the troubleshooting page for details on how to fix this.

To further configure the installed Java APM (e.g., install the APM on Docker and Kubernetes, customize the APM's behaviour using environment variables, enable debugging mode, use head sampling, or enable continous profiling), follow the steps in the configuration page.