Components

OpenTelemetry is currently made up of several main components:

  • Cross-language specification
  • Tools to collect, transform, and export telemetry data
  • Per-language SDKs
  • Automatic instrumentation and contrib packages

OpenTelemetry lets you replace the need for vendor-specific SDKs and tools for generating and exporting telemetry data.

Specification

Describes the cross-language requirements and expectations for all implementations. Beyond a definition of terms, the specification defines the following:

  • API: Defines data types and operations for generating and correlating tracing, metrics, and logging data.
  • SDK: Defines requirements for a language-specific implementation of the API. Configuration, data processing, and exporting concepts are also defined here.
  • Data: Defines the OpenTelemetry Line Protocol (OTLP) and vendor-agnostic semantic conventions that a telemetry backend can provide support for.

For more information, see the Specification.

Additionally, extensively-commented protobuf interface files for API concepts can be found in the proto repository.

Collector

The OpenTelemetry Collector is a vendor-adgnostic proxy that can receive, process, and export telemetry data. It supports receiving telemetry data in multiple formats (e.g., OTLP, Jaeger, Prometheus, as well as many commercial/proprietary tools) and sending data to one or more backends. It also supports processing and filtering telemetry data before it gets exported. Collector contrib packages bring support for more data formats and vendor backends.

For more information, see Data Collection.

Language SDKs

OpenTelemetry also has language SDKs that let you use the OpenTelemetry API to generate telemetry data with your language of choice and export that data to a preferred backend. These SDKs also let you incorporate automatic instrumentation for common libraries and frameworks that you can use to connect to manual instrumentation in your application. Vendors often make distributions of language SDKs to make exporting to their backends simplier.

For more information, see Instrumenting.

Automatic Instrumentation

OpenTelemetry supports a broad number of components that generate relevant telemetry data from popular libraries and frameworks for supported languages. For example, inbound and outbound HTTP requests from an HTTP library will generate data about those requests. Using automatic instrumentation may differ from language to language, where one might prefer or require the use of a component that you load alongside your application, and another might prefer that you pull in a package explicitly in your codebase.

It is a long-term goal that popular libraries are authored to be observable out of the box, such that pulling in a separate component is not required.

For more information, see Instrumenting Libraries.

Last modified December 2, 2021: Sorta redo the components page (#955) (74b39ec)