In today’s world of distributed systems, it’s essential to have visibility into how different components of an application communicate and interact with each other. Distributed tracing provides a solution to this challenge by capturing and correlating information about requests as they flow through multiple services.

In this blog post, we will explore how to implement distributed tracing in Java applications using GlassFish as an application server and OpenTracing as a tracing framework.

What is distributed tracing?

Distributed tracing is a technique to monitor and profile the flow of requests as they travel through multiple services in a distributed system. It involves capturing and recording the timing and context of interactions between various components of an application.

By implementing distributed tracing, developers and operators can gain insights into the performance and behavior of their distributed systems. This information can help identify and diagnose issues, optimize performance, and improve overall system reliability.

Setting up GlassFish

GlassFish is a popular Java application server that supports Enterprise Java applications. To get started, download and install GlassFish on your development machine or server.

Once GlassFish is installed, you’ll need to enable the OpenTracing framework in your application.

Enabling OpenTracing in GlassFish

To enable OpenTracing in GlassFish, you’ll need to add the necessary dependencies to your application.

The following Maven dependencies should be added to your pom.xml file:

<dependency>
    <groupId>io.opentracing</groupId>
    <artifactId>opentracing-api</artifactId>
    <version>0.33.0</version>
</dependency>
<dependency>
    <groupId>io.opentracing.contrib</groupId>
    <artifactId>opentracing-glassfish</artifactId>
    <version>0.1.7</version>
</dependency>

Next, you’ll need to configure GlassFish to use the OpenTracing implementation.

Edit the domain.xml file located at <glassfish_home>/glassfish/domains/domain1/config/ and add the following line inside the <extensions> section:

<extension jar="${com.sun.aas.installRoot}/modules/opentracing-glassfish.jar" name="opentracing-glassfish" />

Finally, you’ll need to configure your application to use OpenTracing.

Create a GlassFishTracer instance and register it with the OpenTracing GlobalTracer:

import io.opentracing.contrib.tracerresolver.TracerResolver;
import io.opentracing.contrib.tracerresolver.GlassFishTracer;

TracerResolver.resolveMultiple().forEach(GlobalTracer::register);

Instrumenting your application

With OpenTracing enabled in GlassFish, you can now instrument your Java application to capture trace information.

Use OpenTracing APIs to create spans and add tags and logs to capture relevant information about the execution of your code. For example:

import io.opentracing.Tracer;
import io.opentracing.util.GlobalTracer;

Tracer tracer = GlobalTracer.get();

Span span = tracer.buildSpan("my-operation").start();
try {
    // Perform your operation here
    // ...
}
catch (Exception e) {
    // Handle exceptions
    span.setTag("error", true);
}
finally {
    span.finish();
}

By adding such instrumentation throughout your application, you can trace the request flow across different components and capture valuable data for analysis and debugging.

Conclusion

Distributed tracing is an essential tool for understanding and optimizing the behavior of distributed systems. By leveraging the power of GlassFish as an application server and OpenTracing as a tracing framework, you can easily implement distributed tracing in your Java applications.

With the ability to capture and analyze distributed traces, you can identify performance bottlenecks, diagnose and resolve issues, and ensure the reliability and scalability of your application.

#Java #DistributedTracing