open-telemetry · jmacd · Oct 15, 2020 · Sep 9, 2020 · Sep 11, 2020 · Sep 11, 2020
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -23,6 +23,8 @@ New:
   ([#697](https://github.com/open-telemetry/opentelemetry-specification/pull/697))
   * API was extended to allow adding arbitrary event attributes ([#874](https://github.com/open-telemetry/opentelemetry-specification/pull/874))
   * `exception.escaped` was added ([#784](https://github.com/open-telemetry/opentelemetry-specification/pull/784))
+- Add semantic conventions for system metrics
+  ([#937](https://github.com/open-telemetry/opentelemetry-specification/pull/937))
 
 Updates:
 

diff --git a/specification/metrics/semantic_conventions/README.md b/specification/metrics/semantic_conventions/README.md
@@ -1,6 +1,11 @@
 # Metrics Semantic Conventions
 
-TODO: Add semantic conventions for metric names and labels.
+The following semantic conventions surrounding metrics are defined:
+
+* [HTTP Metrics](http-metrics.md): Semantic conventions and instruments for HTTP metrics.
+* [System Metrics](system-metrics.md): Semantic conventions and instruments for standard system metrics.
+* [Process Metrics](process-metrics.md): Semantic conventions and instruments for standard process metrics.
+* [Runtime Metrics](runtime-metrics.md): Semantic conventions and instruments for runtime metrics.
 
 Apart from semantic conventions for metrics and [traces](../../trace/semantic_conventions/README.md),
 OpenTelemetry also defines the concept of overarching [Resources](../../resource/sdk.md) with their own

diff --git a/specification/metrics/semantic_conventions/process-metrics.md b/specification/metrics/semantic_conventions/process-metrics.md
@@ -0,0 +1,21 @@
+# Semantic Conventions for Process Metrics
+
+This document describes instruments and labels for common process level
+metrics in OpenTelemetry. Also consider the general [semantic conventions for
+system metrics](system-metrics.md#semantic-conventions) when creating
+instruments not explicitly defined in this document.
+
+<!-- Re-generate TOC with `markdown-toc --no-first-h1 -i` -->
+
+<!-- toc -->
+
+- [Metric Instruments](#metric-instruments)
+  * [Standard Process Metrics - `process.`](#standard-process-metrics---process)
+
+<!-- tocstop -->
+
+## Metric Instruments
+
+### Standard Process Metrics - `process.`
+
+TODO
diff --git a/specification/metrics/semantic_conventions/runtime-metrics.md b/specification/metrics/semantic_conventions/runtime-metrics.md
@@ -0,0 +1,42 @@
+# Semantic Conventions for Runtime Metrics
+
+This document describes instruments and labels for common runtime level
+metrics in OpenTelemetry. Also consider the general [semantic conventions for
+system metrics](system-metrics.md#semantic-conventions) when creating
+instruments not explicitly defined in this document.
+
+<!-- Re-generate TOC with `markdown-toc --no-first-h1 -i` -->
+
+<!-- toc -->
+
+- [Metric Instruments](#metric-instruments)
+  * [Runtime Metrics - `runtime.`](#runtime-metrics---runtime)
+    + [Runtime Specific Metrics - `runtime.{environment}.`](#runtime-specific-metrics---runtimeenvironment)
+
+<!-- tocstop -->
+
+## Metric Instruments
+
+### Runtime Metrics - `runtime.`
+
+Runtime environments vary widely in their terminology, implementation, and
+relative values for a given metric. For example, Go and Python are both
+garbage collected languages, but comparing heap usage between the two
+runtimes directly is not meaningful. For this reason, this document does not
+propose any standard top-level runtime metric instruments. See [OTEP
+108](https://github.com/open-telemetry/oteps/pull/108/files) for additional
+discussion.
+
+#### Runtime Specific Metrics - `runtime.{environment}.`
+
+Runtime level metrics specific to a certain runtime environment should be
+prefixed with `runtime.{environment}.` and follow the semantic conventions
+outlined in [semantic conventions for system
+metrics](system-metrics.md#semantic-conventions). For example, Go runtime
+metrics use `runtime.go.` as a prefix.
+
+Some programming languages have multiple runtime environments that vary
+significantly in their implementation, for example [Python has many
+implementations](https://wiki.python.org/moin/PythonImplementations). For
+these languages, consider using specific `environment` prefixes to avoid
+ambiguity, like `runtime.cpython.` and `runtime.pypy.`.
diff --git a/specification/metrics/semantic_conventions/system-metrics.md b/specification/metrics/semantic_conventions/system-metrics.md
@@ -0,0 +1,153 @@
+# Semantic Conventions for System Metrics
+
+This document describes instruments and labels for common system level
+metrics in OpenTelemetry. Also included are general semantic conventions for
+system, process, and runtime metrics, which should be considered when
+creating instruments not explicitly defined in the specification.
+
+<!-- Re-generate TOC with `markdown-toc --no-first-h1 -i` -->
+
+<!-- toc -->
+
+- [Semantic Conventions](#semantic-conventions)
+  * [Instrument Names](#instrument-names)
+  * [Units](#units)
+- [Metric Instruments](#metric-instruments)
+  * [Standard System Metrics - `system.`](#standard-system-metrics---system)
+    + [`system.cpu.`](#systemcpu)
+    + [`system.memory.`](#systemmemory)
+    + [`system.swap.`](#systemswap)
+    + [`system.disk.`](#systemdisk)
+    + [`system.filesystem.`](#systemfilesystem)
+    + [`system.network.`](#systemnetwork)
+    + [`system.process.`](#systemprocess)
+    + [OS Specific System Metrics - `system.{os}.`](#os-specific-system-metrics---systemos)
+
+<!-- tocstop -->
+
+## Semantic Conventions
+
+The following semantic conventions aim to keep naming consistent. They
+provide guidelines for most of the cases in this specification and should be
+followed for other instruments not explicitly defined in this document.
+
+### Instrument Names
+
+- **usage** - an instrument that measures an amount used out of a known total
+amount should be called `entity.usage`. For example,
+`system.filesystem.usage` for the amount of disk spaced used. A measure of
+the amount of an unlimited resource consumed is differentiated from
+**usage**. This may be time, data, etc.
+- **utilization** - an instrument that measures a *value ratio* of usage
+(like percent, but in the range `[0, 1]`) should be called
+`entity.utilization`. For example, `system.memory.utilization` for the ratio
+of memory in use.
+- **time** - an instrument that measures passage of time should be called
+`entity.time`. For example, `system.cpu.time` with varying values of label
+`state` for idle, user, etc.
+- **io** - an instrument that measures bidirectional data flow should be
+called `entity.io` and have labels for direction. For example,
+`system.network.io`.
+- Other instruments that do not fit the above descriptions may be named more
+freely. For example, `system.swap.page_faults` and `system.network.packets`.
+Units do not need to be specified in the names since they are included during
+instrument creation, but can be added if there is ambiguity.
+
+### Units
+
+- Instruments for utilization metrics (that measure the ratio out of a total)
+SHOULD use units of `1`. Such values represent a *value ratio* and are always
+in the range `[0, 1]`.
+- Instruments that measure an integer count of something SHOULD use semantic
+units like `packets`, `errors`, `faults`, etc.
+
+## Metric Instruments
+
+### Standard System Metrics - `system.`
+
+#### `system.cpu.`
+
+**Description:** System level processor metrics.
+| Name                   | Units   | Instrument Type   | Value Type | Label Key | Label Values                        |
+| ---------------------- | ------- | ----------------- | ---------- | --------- | ----------------------------------- |
+| system.cpu.time        | seconds | SumObserver       | Double     | state     | idle, user, system, interrupt, etc. |
+|                        |         |                   |            | cpu       | 1 - #cores                          |
+| system.cpu.utilization | 1       | UpDownSumObserver | Double     | state     | idle, user, system, interrupt, etc. |
+|                        |         |                   |            | cpu       | 1 - #cores                          |
+
+#### `system.memory.`
+
+**Description:** System level memory metrics.
+| Name                      | Units | Instrument Type   | Value Type | Label Key | Label Values             |
+| ------------------------- | ----- | ----------------- | ---------- | --------- | ------------------------ |
+| system.memory.usage       | bytes | UpDownSumObserver | Int64      | state     | used, free, cached, etc. |
+| system.memory.utilization | 1     | ValueObserver     | Double     | state     | used, free, cached, etc. |
+
+#### `system.swap.`
+
+**Description:** System level swap/paging metrics.
+| Name                         | Units      | Instrument Type   | Value Type | Label Key | Label Values |
+| ---------------------------- | ---------- | ----------------- | ---------- | --------- | ------------ |
+| system.swap.usage            | pages      | UpDownSumObserver | Int64      | state     | used, free   |
+| system.swap.utilization      | 1          | ValueObserver     | Double     | state     | used, free   |
+| system.swap.page\_faults     | faults     | SumObserver       | Int64      | type      | major, minor |
+| system.swap.page\_operations | operations | SumObserver       | Int64      | type      | major, minor |
+|                              |            |                   |            | direction | in, out      |
+
+#### `system.disk.`
+
+**Description:** System level disk performance metrics.
+| Name                         | Units      | Instrument Type | Value Type | Label Key | Label Values |
+| ---------------------------- | ---------- | --------------- | ---------- | --------- | ------------ |
+| system.disk.io<!--notlink--> | bytes      | SumObserver     | Int64      | device    | (identifier) |
+|                              |            |                 |            | direction | read, write  |
+| system.disk.operations       | operations | SumObserver     | Int64      | device    | (identifier) |
+|                              |            |                 |            | direction | read, write  |
+| system.disk.time             | seconds    | SumObserver     | Double     | device    | (identifier) |
+|                              |            |                 |            | direction | read, write  |
+| system.disk.merged           | 1          | SumObserver     | Int64      | device    | (identifier) |
+|                              |            |                 |            | direction | read, write  |
+
+#### `system.filesystem.`
+
+**Description:** System level filesystem metrics.
+| Name                          | Units | Instrument Type   | Value Type | Label Key | Label Values         |
+| ----------------------------- | ----- | ----------------- | ---------- | --------- | -------------------- |
+| system.filesystem.usage       | bytes | UpDownSumObserver | Int64      | device    | (identifier)         |
+|                               |       |                   |            | state     | used, free, reserved |
+| system.filesystem.utilization | 1     | ValueObserver     | Double     | device    | (identifier)         |
+|                               |       |                   |            | state     | used, free, reserved |
+
+#### `system.network.`
+
+**Description:** System level network metrics.
+| Name                            | Units       | Instrument Type   | Value Type | Label Key | Label Values                                                                                   |
+| ------------------------------- | ----------- | ----------------- | ---------- | --------- | ---------------------------------------------------------------------------------------------- |
+| system.network.dropped\_packets | packets     | SumObserver       | Int64      | device    | (identifier)                                                                                   |
+|                                 |             |                   |            | direction | transmit, receive                                                                              |
+| system.network.packets          | packets     | SumObserver       | Int64      | device    | (identifier)                                                                                   |
+|                                 |             |                   |            | direction | transmit, receive                                                                              |
+| system.network.errors           | errors      | SumObserver       | Int64      | device    | (identifier)                                                                                   |
+|                                 |             |                   |            | direction | transmit, receive                                                                              |
+| system<!--notlink-->.network.io | bytes       | SumObserver       | Int64      | device    | (identifier)                                                                                   |
+|                                 |             |                   |            | direction | transmit, receive                                                                              |
+| system.network.connections      | connections | UpDownSumObserver | Int64      | device    | (identifier)                                                                                   |
+|                                 |             |                   |            | protocol  | tcp, udp, [etc.](https://en.wikipedia.org/wiki/Transport_layer#Protocols)                      |
+|                                 |             |                   |            | state     | [e.g. for tcp](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#Protocol_operation) |
+
+#### `system.process.`
+
+**Description:** System level aggregate process metrics. For metrics at the
+individual process level, see [process metrics](process-metrics.md).
+| Name                 | Units     | Instrument Type | Value Type | Label Key | Label Values                                                                                   |
+| -------------------- | --------- | --------------- | ---------- | --------- | ---------------------------------------------------------------------------------------------- |
+| system.process.count | processes | SumObserver     | Int64      | status    | running, sleeping, [etc.](https://man7.org/linux/man-pages/man1/ps.1.html#PROCESS_STATE_CODES) |
+
+#### OS Specific System Metrics - `system.{os}.`
+
+Instrument names for system level metrics that have different and conflicting
+meaning across multiple OSes should be prefixed with `system.{os}.` and
+follow the hierarchies listed above for different entities like CPU, memory,
+and network. For example, an instrument for measuring the load average on
+Linux could be named `system.linux.cpu.load`, reusing the `cpu` name proposed
+above.