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

java --version

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Install

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Step 1: Download JAR File

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 3.

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Docker

Add the following environment variable to your application:

MW_AGENT_SERVICE=<DOCKER_BRIDGE_GATEWAY_ADDRESS>

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Kubernetes

Run the following command to find the mw-service in Kubernetes:

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Kubernetes

Run the following command to find the mw-service in Kubernetes:

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

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>

Run the following command to download the above dependencies:

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

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Continuous Profiling

Continuous profiling captures real-time performance insights from your application to enable rapid identification of resource allocation, bottlenecks, and more. Navigate to the Continuous Profiling section to learn more about using Continuous Profiling with the Java APM.