#Non-Intrusive Integration of Tracing in Java Applications

#Feature Overview

Tracing is a core capability of observability in distributed systems, which can fully record the call paths and performance data of requests within the system. This article describes how to achieve non-intrusive integration of tracing in Java applications using the automatic injection of the OpenTelemetry Java Agent.

#Use Cases

Java applications can be integrated for the following scenarios:

• Quickly adding tracing capabilities to Java applications
• Avoiding modifications to the application source code
• Deploying services with Kubernetes
• Visualizing service inter-call relationships and analyzing performance bottlenecks

#Prerequisites

Before using this feature, ensure that:

• The target service is deployed on the Alauda Container Platform
• The service is using JDK version Java 8 or higher
• You have editing permissions for the Deployment in the target namespace
• The platform has completed tracing deployment

#Steps to Operate

For a Java application that needs to be integrated into the Alauda Container Platform tracing, the following adaptations are required:

• Configure automatic injection annotations for the Java Deployment.
• Set the SERVICE_NAME environment variable.
• Set the SERVICE_NAMESPACE environment variable.

Example of Deployment adaptation:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-java-deploy
spec:
  template:
    metadata:
      annotations:
        instrumentation.opentelemetry.io/inject-java: cpaas-system/acp-common-java
      labels:
        app.kubernetes.io/name: my-java-app
    spec:
      containers:
      - env:
        - name: SERVICE_NAME
          valueFrom:
            fieldRef:
              apiVersion: v1
              fieldPath: metadata.labels['app.kubernetes.io/name']
        - name: SERVICE_NAMESPACE
          valueFrom:
            fieldRef:
              apiVersion: v1
              fieldPath: metadata.namespace

#Operation Results

After adapting the Java application:

• If the newly started Java application pod contains the opentelemetry-auto-instrumentation-java init container, it indicates that the injection was successful.
• Send test requests to the Java application.
• In the Container Platform view, select the project, cluster, and namespace where the Java application resides.
• Navigate to the Observability -> Tracing page to view the tracing data and timeline waterfall diagram of the Java application.