library

Library Instrumentation for Netty version 4.1 and higher

Provides OpenTelemetry instrumentation for Netty, enabling HTTP client and server spans and metrics.

Quickstart

Add these dependencies to your project

Replace OPENTELEMETRY_VERSION with the latest release.

For Maven, add to your pom.xml dependencies:

<dependencies>
  <dependency>
    <groupId>io.opentelemetry.instrumentation</groupId>
    <artifactId>opentelemetry-netty-4.1</artifactId>
    <version>OPENTELEMETRY_VERSION</version>
  </dependency>
</dependencies>

For Gradle, add to your dependencies:

implementation("io.opentelemetry.instrumentation:opentelemetry-netty-4.1:OPENTELEMETRY_VERSION")

Usage

HTTP Client

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.http.HttpClientCodec;
import io.opentelemetry.api.OpenTelemetry;
import io.opentelemetry.context.Context;
import io.opentelemetry.instrumentation.netty.v4_1.NettyClientTelemetry;

// Get an OpenTelemetry instance
OpenTelemetry openTelemetry = ...;

NettyClientTelemetry clientTelemetry = NettyClientTelemetry.create(openTelemetry);

EventLoopGroup eventLoopGroup = ...; // Use appropriate EventLoopGroup for your platform
Class<? extends Channel> channelClass = ...; // Use appropriate Channel class for your platform

Bootstrap bootstrap = new Bootstrap();
bootstrap.group(eventLoopGroup)
    .channel(channelClass)
    .handler(new ChannelInitializer<SocketChannel>() {
        @Override
        protected void initChannel(SocketChannel ch) {
            ch.pipeline()
                .addLast(new HttpClientCodec())
                .addLast(clientTelemetry.createCombinedHandler())
                .addLast(new YourClientHandler()); // Your application handler
        }
    });

Channel channel = bootstrap.connect("localhost", 8080).sync().channel();
NettyClientTelemetry.setParentContext(channel, Context.current());

HTTP Server

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.ServerChannel;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.http.HttpServerCodec;
import io.opentelemetry.api.OpenTelemetry;
import io.opentelemetry.instrumentation.netty.v4_1.NettyServerTelemetry;

// Get an OpenTelemetry instance
OpenTelemetry openTelemetry = ...;

NettyServerTelemetry serverTelemetry = NettyServerTelemetry.create(openTelemetry);

EventLoopGroup bossGroup = ...; // Use appropriate EventLoopGroup for your platform
EventLoopGroup workerGroup = ...; // Use appropriate EventLoopGroup for your platform
Class<? extends ServerChannel> serverChannelClass = ...; // Use appropriate ServerChannel class for your platform

ServerBootstrap bootstrap = new ServerBootstrap();
bootstrap.group(bossGroup, workerGroup)
    .channel(serverChannelClass)
    .childHandler(new ChannelInitializer<SocketChannel>() {
        @Override
        protected void initChannel(SocketChannel ch) {
            ch.pipeline()
                .addLast(new HttpServerCodec())
                .addLast(serverTelemetry.createCombinedHandler())
                .addLast(new YourServerHandler()); // Your application handler
        }
    });

bootstrap.bind(8080).sync();