OpenTelemetry Auto-Instrumentation for Java

Notice - Work in Progress!

This project is still in the early phases of development and is not yet stable. You are welcome to experiment with it, but we strongly discourage any production use!

Introduction

This project uses a technique known as bytecode instrumentation to add tracing to a Java application. Simply put, we provide a Java agent that can be attached to any Java 7+ application and dynamically adds code to enable tracing.

Using the agent

As mentioned above, this project is in a very early phase of development and not yet stable. However, you can try it on your Java application by following these instructions.

Download and run

Download the latest release.

The instrumentation agent is enabled using the -javaagent flag to the JVM. Configuration parameters are passed as Java system properties (-D flags) or as environment variables. This is an example:

java -javaagent:/path/to/opentelemetry-auto-<version>.jar \
     -Dota.exporter.jar=exporter-adapters/logging-exporter-adapter/build/libs/logging-exporter-adapter-0.1.2-SNAPSHOT.jar \
     -Dota.jaeger.host=localhost \
     -Dota.jaeger.port=14250 \
     -Dota.service=shopping \
     -jar myapp.jar

Configuration parameters (subject to change!)

System property	Environment variable	Purpose
ota.exporter.jar	OTA_EXPORTER_JAR	The path to an exporter JAR
ota.service	OTA_SERVICE	The service name of this JVM instance. This is used as a label in Jaeger to distinguish between JVM instances in a multi-service environment.

Available exporters

Currently two exporters are available and bundled with this project. They area available under the exporter-adapters directory.

Logging Exporter

The logging exporter simply prints the name of the span along with its attributes to stdout. It is used manly for testing and debugging. It takes a single configuration parameter.

System property	Environment variable	Purpose
ota.exporter.logging.prefix	OTA_EXPORTER_LOGGING_PREFIX	A string that is printed in front of the span name and attributes.

Jaeger exporter

A simple wrapper for the Jaeger exporter of opentelemetry-java. It currently only supports gRPC as its communications protocol.

System property	Environment variable	Purpose
ota.exporter.jaeger.host	OTA_EXPORTER_JAEGER_HOST	The Jaeger host to connect to. Currently only gRPC is supported.
ota.exporter.jaeger.port	OTA_EXPORTER_JAEGER_PORT	The port to connect to on the Jaeger host. Currently only gRPC is supported

These parameter names are very likely to change over time, so please check back here when trying out a new version!

Please report any bugs or unexpected behavior you may find.

Building from source

Build using Java 8:

gradle assemble

and then you can find the java agent artifact at java-agent/build/lib/opentelemetry-auto-<version>.jar.