OpenTelemetry

OpenTelemetry is an open source observability framework providing a vendor-neutral way to instrument, generate, collect and export telemetry, covering traces, metrics, logs, baggage and profiles as distinct signals.

Being a standard rather than a product is the whole point, and it changed the economics of this market. Before it, instrumenting an application meant embedding a specific vendor's agent throughout the codebase, which made changing observability supplier a rewriting project rather than a procurement decision. Instrumenting once against OpenTelemetry and pointing the output wherever you like turns that back into a commercial choice, which is why nearly every vendor in the category now advertises support for it.

Zero-code instrumentation is the practical on-ramp and it deserves emphasis. Adding observability to an existing service without modifying it, by attaching an agent that instruments common libraries automatically, means a team can get traces out of software nobody wants to touch. Code-based instrumentation then adds the application-specific detail where it matters.

Semantic conventions are the quietly important part: agreeing what an attribute for an HTTP method or a database system is called means telemetry from different languages and libraries can be queried together, which is the difference between a standard and a wire format. The Collector receives, processes and exports data with sampling including tail-based sampling, and the project publishes a full demo architecture of instrumented microservices. Documentation is available in a dozen languages. OpenTelemetry is free and open source under the Cloud Native Computing Foundation.