Adrian Cole codefromthecrypt

I've had many people ask me questions about OpenTracing, often in relation to OpenZipkin. I've seen assertions about how it is vendor neutral and is the lock-in cure. This post is not a sanctioned, polished or otherwise muted view, rather what I personally think about what it is and is not, and what it helps and does not help with. Scroll to the very end if this is too long. Feel free to add a comment if I made any factual mistakes or you just want to add a comment.

So, what is OpenTracing?

OpenTracing is documentation and library interfaces for distributed tracing instrumentation. To be "OpenTracing" requires bundling its interfaces in your work, so that others can use it to time distributed operations with the same library.

So, who is it for?

OpenTracing interfaces are targeted to authors of instrumentation libraries, and those who want to collaborate with traces created by them. Ex something started a trace somewhere and I add a notable event to that trace. Structure logging was recently added to O

Questions come up some times about why things get bad data. It is hard to pin things down, as maybe you can't modify the code, or even know where to look. Here's an example of how to track down what's making bad trace ids in finagle.

Firstly, download and extract byteman so you can use it.

$ (cd /tmp; wget -q http://downloads.jboss.org/byteman/3.0.5/byteman-download-3.0.5-bin.zip; unzip byteman-download-3.0.5-bin.zip)
$ export BYTEMAN_HOME=/tmp/byteman-download-3.0.5/

	I made this with https://textik.com in attempts to explain how service naming work. Since english is
	second language for many coders, diagrams help. In this case, achieved understanding in <20 minutes!


	The tracer on Server A starts a trace since is doesn't read
	headers or anything from the browser's request. In zipkin
	this has annotation "sr" with the serviceName "loginService"
	-\
	-\ Server A has role loginService, so its tracer is named that.
	Browser -\+--------------+

	public final class HttpClient4Instrumentation {

	public static class Config extends ClientHandler.Config<HttpRequest, HttpResponse> {
	@Override protected Parser<HttpRequest, String> spanNameParser() {
	return r -> r.getRequestLine().getMethod();
	}

	@Override protected TagsParser<HttpRequest> requestTagsParser() {
	return TagsParser.builder(HttpRequest.class)
	.addParser(TraceKeys.HTTP_URL, input -> input.getRequestLine().getUri())

	[
	{
	"traceId": "4e441824ec2b6a44",
	"id": "4e441824ec2b6a44",
	"name": "get",
	"timestamp": 1477975620117000,
	"duration": 500209,
	"annotations": [
	{
	"timestamp": 1477975620117000,

	/**
	* Instrumentation should set {@link Span#timestamp} when recording a span so that guess-work
	* isn't needed. Since a lot of instrumentation don't, we have to make some guesses.
	*
	* <pre><ul>
	* <li>If there is a {@link Constants#CLIENT_SEND}, use that</li>
	* <li>Fall back to {@link Constants#SERVER_RECV}, if a root span</li>
	* <li>Otherwise, return null</li>
	* </ul></pre>
	*/

	CodecBenchmarks.writeClientSpan_json_zipkin avgt 15 1.445 ± 0.036 us/op
	CodecBenchmarks.writeClientSpan_thrift_libthrift avgt 15 1.951 ± 0.014 us/op
	CodecBenchmarks.writeClientSpan_thrift_zipkin avgt 15 0.433 ± 0.011 us/op
	CodecBenchmarks.writeLocalSpan_json_zipkin avgt 15 0.813 ± 0.010 us/op
	CodecBenchmarks.writeLocalSpan_thrift_libthrift avgt 15 1.191 ± 0.016 us/op
	CodecBenchmarks.writeLocalSpan_thrift_zipkin avgt 15 0.268 ± 0.004 us/op
	CodecBenchmarks.writeRpcSpan_json_zipkin avgt 15 3.606 ± 0.068 us/op
	CodecBenchmarks.writeRpcSpan_thrift_libthrift avgt 15 5.134 ± 0.081 us/op
	CodecBenchmarks.writeRpcSpan_thrift_zipkin avgt 15 1.384 ± 0.078 us/op
	CodecBenchmarks.writeRpcV6Span_json_zipkin avgt 15 3.912 ± 0.115 us/op

	/**
	* Copyright 2016 The OpenZipkin Authors
	*
	* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
	* in compliance with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software distributed under the License
	* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express

	$ docker inspect 97f9b5dc9c2f
	[
	{
	"Id": "97f9b5dc9c2f850f808ffa73893e0152d543437a917bdb6d05eb6b606fe5f54c",
	"Created": "2016-08-25T08:08:12.540730023Z",
	"Path": "/bin/sh",
	"Args": [
	"-c",
	"test -n \"$STORAGE_TYPE\" \u0026\u0026 source .${STORAGE_TYPE}_profile; java ${JAVA_OPTS} -cp . org.springframework.boot.loader.JarLauncher"
	],