Opentelemetry

Many tools that profile Go binaries resolve function names from the ELF symbol table or DWARF debug info, and production builds strip both. Point one of those profilers at a stripped binary and you get addresses, not names. The opentelemetry-ebpf-profiler doesn’t have this problem, and we’re going to find out why. Let’s start with a binary rather than a profiler. Here is the whole program, with //go:noinline so the compiler can’t fold checkout into main: ...

Note This post was originally published on the OpenTelemetry blog on 2026-07-16. I wrote it for the OpenTelemetry community; this is a mirror on my personal blog with some added commentary. Why this milestone matters to me I have been involved with the Go Compile-Time Instrumentation SIG since it kicked off at the start of 2025, when Alibaba and Datadog decided to pool their efforts into a single vendor-neutral project. Watching it reach v1 last week felt genuinely satisfying — not because “v1” is a magic number, but because it marks the point where we stopped calling it experimental and started calling it something people should actually run in their builds. ...

We’re going to instrument a Go program without touching its source, and the whole change fits in one build command. Here’s the before and after: 1 2 go build -o myapp . otelc go build -o myapp . Same flags, same package, one extra word in front. The binary that comes out has OpenTelemetry instrumentation compiled in for the libraries otelc knows about, net/http and gRPC among them, and nobody opened a handler file. ...

Take one HTTP request, GET /orders/42, headed for a Go service nobody is going to rebuild this quarter. We want a span for it, another for its database call, and the trace context handed on to the next service, all without touching the service. “Zero code changes” travels far in conference talks and vendor docs. Today we watch that one request from the kernel and find out where the phrase holds. ...

Start a Java service with one extra flag and it gets traced, with no source change and no rebuild: 1 java -javaagent:agent.jar -jar app.jar The JVM offers each class’s bytes to the agent’s ClassFileTransformer before it defines the class, so the agent can rewrite a method on its way in. Python lets you swap a method at runtime, which is the monkey-patching of the title. That flag is Java’s agent slot, and Python doesn’t even need one. Go has no such slot, and that follows from how Go was designed. ...