Java

This guide walks you through setting up Application Performance Monitoring (APM) on a Java application. These instructions can also be found on the Installation page in your Middleware Account. View example code here.

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Prerequisites

• Middleware Host Agent (MW Agent), to install the MW Agent please see our installation guide.
• Java 8+, you can check your Java version with the following command.

java --version

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Step 1: Download JAR

Download the latest Middleware instrumentation JAR file from the Github release page.

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Step 2: Container Variables

Applications running in a container require an additional environment variable. If your application is not running in a container, move to Step 5.

For Docker containers, add the following environment variable to your application.

MW_AGENT_SERVICE=<DOCKER_BRIDGE_GATEWAY_ADDRESS>

kubectl get service --all-namespaces | grep mw-service

Then add the following environment variable to your application deployment YAML file.

MW_AGENT_SERVICE=mw-service.mw-agent-ns.svc.cluster.local

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Step 3: Capture Application Data

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Traces

Distributed tracing will be automatically enabled upon completing Step 4: Run Application.

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Metrics

Metrics collection will be automatically enabled upon completing Step 4: Run Application.

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Application & Custom Logs

Application Logs will be automatically enabled upon completing Step 4: Run Application.

To add custom logs, add this dependency in the pom.xml file.

<dependency>
  <groupId>io.github.middleware-labs</groupId>
  <artifactId>agent-apm-java</artifactId>
  <version>0.0.16</version>
</dependency>

Install the package into the local repository.

mvn install

Import the logger package.

import io.github.middlewarelabs.agentapmjava.Logger;

Then utilize the following functions based on desired log severity levels.

Logger.info("info message");
Logger.debug("debug message");
Logger.warn("warn message");
Logger.error("error message");

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Profiling

Application Profiling is automatically enabled upon completing Step 4: Run Application.

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Stack Traces

Use the Logger.recordError(e) method to record a stack trace when an error occurs. See an example of this method below.

import io.github.middlewarelabs.agentapmjava.Logger;
        
try {
       int[] myNumbers = {1, 2, 3};
       System.out.println(myNumbers[10]);
     } catch (Throwable  e) {
       Logger.recordError(e);
       System.out.println("Something went wrong.");
     }

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Step 4: Run Application

Run your application with the command given below.

MW_API_KEY={MW_API_KEY} java -javaagent:/PATH/TO/middleware-javaagent-{version}.jar \
    -Dotel.service.name={APM-SERVICE-NAME} \
    -Dotel.resource.attributes=project.name={APM-PROJECT-NAME} \
    -jar <YOUR_APP>.jar