README.md

OpenTelemetry SDK Extension zPages

This module contains code for the OpenTelemetry Java zPages, which are a collection of dynamic HTML web pages embedded in your app that display stats and trace data. Learn more in this blog post.

Register the zPages

Note: The package com.sun.net.httpserver is required to use the default zPages setup. Please make sure your version of the JDK includes this package.

To set-up the zPages, simply call ZPageServer.startHttpServerAndRegisterAllPages(int port) in your main function:

public class MyMainClass {
  public static void main(String[] args) throws Exception {
    ZPageServer.startHttpServerAndRegisterAllPages(8080);
    // ... do work
  }
}

Alternatively, you can call ZPageServer.registerAllPagesToHttpServer(HttpServer server) to register the zPages to a shared server:

public class MyMainClass {
  public static void main(String[] args) throws Exception {
    HttpServer server = HttpServer.create(new InetSocketAddress(8000), 10);
    ZPageServer.registerAllPagesToHttpServer(server);
    server.start();
    // ... do work
  }
}

Access the zPages

View all available zPages on the / index page

The index page / lists all available zPages with a link and description.

View trace spans on the /tracez zPage

The /tracez zPage displays information on running spans, sample span latencies, and sample error spans. The data is aggregated into a summary-level table:

You can click on each of the counts in the table cells to access the corresponding span details. For example, here are the details of the ChildSpan latency sample (row 1, col 4):

View and update the tracing configuration on the /traceconfigz zPage

The /traceconfigz zPage displays information about the currently active tracing configuration and provides an interface for users to modify relevant parameters. Here is what the web page looks like:

Benchmark Testing

This module contains two sets of benchmark tests: one for adding spans to an instance of TracezSpanBuckets and another for retrieving counts and spans with TracezDataAggregator. You can run the tests yourself with the following commands:

./gradlew -PjmhIncludeSingleClass=TracezSpanBucketsBenchmark clean :opentelemetry-sdk-extension-zpages:jmh
./gradlew -PjmhIncludeSingleClass=TracezDataAggregatorBenchmark clean :opentelemetry-sdk-extension-zpages:jmh