What is OpenTelemetry?

A short explanation of what OpenTelemetry is, and is not.

Microservices architectures have enabled developers to build and release software faster and with greater independence, as they were no longer beholden to the elaborate release processes associated with monolithic architectures.

As these now-distributed systems scaled, it became increasingly difficult for developers to see how their own services depend on or affect other services, especially after a deployment or during an outage, where speed and accuracy are critical.

Observability has made it possible for both developers and operators to gain that visibility into their systems.

So what?

In order to make a system observable, it must be instrumented. That is, the code must emit traces, metrics, and logs. The instrumented data must then be sent to an Observability back-end. There are a number of Observability back-ends out there, ranging from self-hosted open source tools (e.g. Jaeger and Zipkin), to commercial SaaS offerings.

In the past, the way in which code was instrumented would vary, as each Observability back-end would have its own instrumentation libraries and agents for emitting data to the tools.

This meant that there was no standardized data format for sending data to an Observability back-end. Furthermore, if a company chose to switch Observability back-ends, it meant that they would have to re-instrument their code and configure new agents just to be able to emit telemetry data to the new tool of choice.

With a lack of standardization, the net result is the lack of data portability and the burden on the user to maintain instrumentation libraries.

Recognizing the need for standardization, the cloud community came together, and two open source projects were born: OpenTracing (a Cloud Native Computing Foundation (CNCF) project) and OpenCensus (a Google Open Source community project).

OpenTracing provided a vendor-neutral API for sending telemetry data over to an Observability back-end; however, it relied on developers to implement their own libraries to meet the specification.

OpenCensus provided a set of language-specific libraries that developers could use to instrument their code and send to any one of their supported back-ends.

Hello, OpenTelemetry!

In the interest of having one single standard, OpenCensus and OpenTracing were merged to form OpenTelemetry (OTel for short) in May 2019. As a CNCF incubating project, OpenTelemetry takes the best of both worlds, and then some.

OTel’s goal is to provide a set of standardized vendor-agnostic SDKs, APIs, and tools for ingesting, transforming, and sending data to an Observability back-end (i.e. open source or commercial vendor).

What can OpenTelemetry do for me?

OTel has broad industry support and adoption from cloud providers, vendors and end users. It provides you with:

  • A single, vendor-agnostic instrumentation library per language with support for both automatic and manual instrumentation.
  • A single vendor-neutral collector binary that can be deployed in a variety of ways.
  • An end-to-end implementation to generate, emit, collect, process and export telemetry data.
  • Full control of your data with the ability to send data to multiple destinations in parallel through configuration.
  • Open-standard semantic conventions to ensure vendor-agnostic data collection
  • The ability to support multiple context propagation formats in parallel to assist with migrating as standards evolve.
  • A path forward no matter where you are on your observability journey.

With support for a variety of open source and commercial protocols, format and context propagation mechanisms as well as providing shims to the OpenTracing and OpenCensus projects, it is easy to adopt OpenTelemetry.

What OpenTelemetry is not

OpenTelemetry is not an observability back-end like Jaeger or Prometheus. Instead, it supports exporting data to a variety of open source and commercial back-ends. It provides a pluggable architecture so additional technology protocols and formats can be easily added.

What next?