Skip to content
Merged
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
55 changes: 31 additions & 24 deletions specification/appendix-d-observability.md
Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,7 @@ sidebar_position: 5
# Appendix D: Observability

This document describes conventions for extracting data from the OpenFeature SDK for use in telemetry signals.
It primarily focuses on providing recommendations for mapping well-known fields in OpenFeature to [OpenTelemetry feature-flag log records](https://opentelemetry.io/docs/specs/semconv/feature-flags/feature-flags-logs/) and other semantic conventions.
It primarily focuses on providing recommendations for mapping well-known fields in OpenFeature to [OpenTelemetry feature-flag log records][otel-ff-logs] and other semantic conventions.

## Evaluations

Expand All @@ -19,42 +19,49 @@ This is particularly relevant to telemetry-related [hooks](./sections/04-hooks.m

The following describes how fields on the [evaluation details](types.md#evaluation-details) are mapped to feature flag log records:

| Log Record Attribute | Source Field or Derived Value from Evaluation Details | Notes |
| --------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------- |
| `feature_flag.key` | `flag key` | See: [flag key](./glossary.md#flag-key) |
| `error.type` | `error code` | See: [error code](./types.md#error-code) |
| `feature_flag.variant` | `variant` | See: [variant](./glossary.md#variant) |
| `feature_flag.evaluation.error.message` | `error message` | A human-readable error message associated with a failed evaluation. For programmatic purposes, refer to `error code`. |
| `feature_flag.evaluation.reason` | `reason` | See: [reason](./types.md#resolution-reason) |
| `feature_flag.evaluation.value.type` | One of `"array"`, `"boolean"`, `"byte_array"`, `"float"`, `"int"`, `"map"`, `"null"`, `"string"` or `"unknown"`, representing the type of the `evaluation details'` `value` field | See: [reason](./types.md#resolution-reason) |

> [!NOTE]
> The `error.type` and `feature_flag.evaluation.reason` enumerations use a lowercase "snake_case" convention (see [OpenTelemetry feature-flag log records](https://opentelemetry.io/docs/specs/semconv/feature-flags/feature-flags-logs/)).
| Log Record Attribute | Source Field or Derived Value from Evaluation Details | Requirement level | Notes |
| --------------------------------------- | ----------------------------------------------------- | ----------------------------- | --------------------------------------------------------------------------------------------------------------------- |
| `feature_flag.key` | `flag key` | `Required` | See: [flag key](./glossary.md#flag-key) |
| `error.type` | `error code` | `Conditionally Required` [^1] | See: [error code](./types.md#error-code), |
| `feature_flag.evaluation.error.message` | `error message` | `Conditionally Required` [^1] | A human-readable error message associated with a failed evaluation. For programmatic purposes, refer to `error code`. |
| `feature_flag.variant` | `variant` | `Conditionally Required` [^2] | See: [variant](./glossary.md#variant) |
| `feature_flag.evaluation.reason` | `reason` | `Recommended` | See: [reason](./types.md#resolution-reason) |

> [!NOTE]
> The `error.type` and `feature_flag.evaluation.reason` enumerations use a lowercase "snake_case" convention (see [OpenTelemetry feature-flag log records][otel-ff-logs]).
> OpenFeature [error codes](types.md#error-code) and [resolution reasons](./types.md#resolution-reason) should be transformed accordingly by integrations which include this data.

#### Flag Value

The flag value is required if the `feature_flag.variant` is not set (and optional otherwise), and is defined in a the event body:

| Body Field | Source Field from Evaluation Details | Notes |
| ---------- | ------------------------------------ | ------------------------------------------- |
| `value` | `value` | The type of the `value` field is undefined. |
| Body Field | Source Field from Evaluation Details | Requirement level | Notes |
| ---------- | ------------------------------------ | ----------------------------- | ------------------------------------------- |
| `value` | `value` | `Conditionally Required` [^3] | The type of the `value` field is undefined. |

### Flag Metadata

The following describes how keys in [flag metadata](types.md#flag-metadata) are mapped to feature flag log records:

| Log Record Attribute | Flag Metadata Key | Notes |
| ------------------------- | ----------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `feature_flag.context.id` | `contextId` | The context identifier returned in the flag metadata uniquely identifies the subject of the flag evaluation. If not available, the [targeting key](./glossary.md#targeting-key) should be used. |
| `feature_flag.set.id` | `flagSetId` | A logical identifier for the [flag set](./glossary.md#flag-set). |
| `feature_flag.version` | `version` | A version string (format unspecified) for the flag or [flag set](./glossary.md#flag-set). |
| Log Record Attribute | Flag Metadata Key | Requirement level | Notes |
| ------------------------- | ----------------- | ----------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `feature_flag.context.id` | `contextId` | `Recommended` | The context identifier returned in the flag metadata uniquely identifies the subject of the flag evaluation. If not available, the [targeting key](./glossary.md#targeting-key) should be used. |
| `feature_flag.set.id` | `flagSetId` | `Recommended` | A logical identifier for the [flag set](./glossary.md#flag-set). |
| `feature_flag.version` | `version` | `Recommended` | A version string (format unspecified) for the flag or [flag set](./glossary.md#flag-set). |

> [!NOTE]
> [!NOTE]
> Keys in flag metadata use the "camelCase" casing convention, while the OpenTelemetry standard uses a namespaced "snake_case" convention.

### Provider Metadata

| Log Record Attribute | Provider Metadata Field | Notes |
| ---------------------------- | ----------------------- | ------------------------------------------------------------------------------------------------ |
| `feature_flag.provider_name` | `name` | The name of the provider as defined in the `provider metadata`, available in the `hook context`. |
| Log Record Attribute | Provider Metadata Field | Requirement level | Notes |
| ---------------------------- | ----------------------- | ----------------- | ------------------------------------------------------------------------------------------------ |
| `feature_flag.provider_name` | `name` | `Recommended` | The name of the provider as defined in the `provider metadata`, available in the `hook context`. |

## Footnotes

[^1]: Include if and only if an error occurred during a flag evaluation.
[^2]: The `variant` field is required if the `value` field is not set.
[^3]: The `value` field is required if the `variant` field is not set.

[otel-ff-logs]: https://opentelemetry.io/docs/specs/semconv/feature-flags/feature-flags-logs/
Loading