Semantic Conventions for Hardware Metrics

Status: Experimental

This document describes instruments and attributes for common hardware level metrics in OpenTelemetry. Consider the general metric semantic conventions when creating instruments not explicitly defined in the specification.

Common hardware attributes

All metrics in hw. instruments should be attached to a Host Resource and therefore inherit its attributes, like host.id and host.name.

Additionally, all metrics in hw. instruments have the following attributes:

Attribute Key	Description	Example	Requirement Level
id	An identifier for the hardware component, unique within the monitored host	win32battery_battery_testsysa33_1	Required
name	An easily-recognizable name for the hardware component	eth0	Recommended
parent	Unique identifier of the parent component (typically the id attribute of the enclosure, or disk controller)	dellStorage_perc_0	Recommended

Metric Instruments

hw. - Common hardware metrics

The below metrics apply to any type of hardware component.

Name	Description	Units	Instrument Type (*)	Value Type	Attribute Key(s)	Attribute Values
hw.energy	Energy consumed by the component, in joules	J	Counter	Int64
hw.errors	Number of errors encountered by the component	{error}	Counter	Int64	hw.error.type (Recommended)
hw.power	Instantaneous power consumed by the component, in Watts (hw.energy is preferred)	W	Gauge	Double
hw.status	Operational status: 1 (true) or 0 (false) for each of the possible states		UpDownCounter	Int	state (Required)	ok, degraded, failed

These common hw. metrics must include the below attributes to describe the monitored component:

Attribute Key	Description	Example	Requirement Level
hw.type	Type of the component	battery, cpu, disk_controller, enclosure, fan, gpu, logical_disk, memory, network, physical_disk, power_supply, tape_drive, temperature, voltage	Required

Warning

hw.status is currently specified as an UpDownCounter but would ideally be represented using a StateSet as defined in OpenMetrics. This semantic convention will be updated once StateSet is specified in OpenTelemetry. This planned change is not expected to have any consequence on the way users query their timeseries backend to retrieve the values of hw.status over time.

hw.host. - Physical host metrics

Description: Physical system as opposed to a virtual system or a container. Examples: physical server, switch or disk array.

Name	Description	Units	Instrument Type (*)	Value Type	Attribute Key(s)	Attribute Values
hw.host.ambient_temperature	Ambient (external) temperature of the physical host	Cel	Gauge	Double
hw.host.energy	Total energy consumed by the entire physical host, in joules	J	Counter	Int64
hw.host.heating_margin	By how many degrees Celsius the temperature of the physical host can be increased, before reaching a warning threshold on one of the internal sensors	Cel	Gauge	Double
hw.host.power	Instantaneous power consumed by the entire physical host in Watts (hw.host.energy is preferred)	W	Gauge	Double

Note The overall energy usage of a host MUST be reported using the specific hw.host.energy and hw.host.power metrics only, instead of the generic hw.energy and hw.power described in the previous section, to prevent summing up overlapping values.

hw.battery. - Battery metrics

Description: A battery in a computer system or an UPS.

Name	Description	Units	Instrument Type (*)	Value Type	Attribute Key(s)	Attribute Values
hw.battery.charge	Remaining fraction of battery charge	1	Gauge	Double
hw.battery.charge.limit	Lower limit of battery charge fraction to ensure proper operation	1	Gauge	Double	limit_type (Recommended)	critical, throttled, degraded
hw.battery.time_left	Time left before battery is completely charged or discharged	s	Gauge	Int	state (Conditionally Required, if the battery is charging or discharging)	charging, discharging
hw.status	Operational status: 1 (true) or 0 (false) for each of the possible states		UpDownCounter	Int	state (Required)	ok, degraded, failed, charging, discharging
					hw.type	battery

All hw.battery. metrics may include the below Recommended attributes to describe the characteristics of the monitored battery:

Attribute Key	Description	Example
chemistry	Chemistry of the battery	Nickel-Cadmium, Lithium-ion
capacity	Design capacity in Watts-hours or Amper-hours	9.3Ah
model	Descriptive model name
vendor	Vendor name

hw.cpu. - Physical processor metrics

Description: Physical processor (as opposed to the logical processor seen by the operating system for multi-core systems). A physical processor may include many individual cores.

Name	Description	Units	Instrument Type (*)	Value Type	Attribute Key	Attribute Values
hw.errors	Total number of errors encountered and corrected by the CPU	{error}	Counter	Int64	hw.type (Required)	cpu
hw.cpu.speed	CPU current frequency	Hz	Gauge	Int64
hw.cpu.speed.limit	CPU maximum frequency	Hz	Gauge	Int64	limit_type (Recommended)	throttled, max, turbo
hw.status	Operational status: 1 (true) or 0 (false) for each of the possible states		UpDownCounter	Int	state (Required)	ok, degraded, failed, predicted_failure
					hw.type (Required)	cpu

Additional Recommended attributes:

Attribute Key	Description	Example
model	Descriptive model name
vendor	Vendor name

hw.disk_controller. - Disk controller metrics

Description: Controller that controls the physical disks and organize them in RAID sets and logical disks that are exposed to the operating system.

Name	Description	Units	Instrument Type (*)	Value Type	Attribute Key	Attribute Values
hw.status	Operational status: 1 (true) or 0 (false) for each of the possible states		UpDownCounter	Int	state (Required)	ok, degraded, failed
					hw.type (Required)	disk_controller

Additional Recommended attributes:

Attribute Key	Description	Example
bios_version	BIOS version
driver_version	Driver for the controller
firmware_version	Firmware version
model	Descriptive model name
serial_number	Serial number
vendor	Vendor name

hw.enclosure. - Enclosure metrics

Description: Computer chassis (can be an expansion enclosure)

Name	Description	Units	Instrument Type (*)	Value Type	Attribute Key	Attribute Values
hw.status	Operational status: 1 (true) or 0 (false) for each of the possible states		UpDownCounter	Int	state (Required)	ok, degraded, failed, open
					hw.type (Required)	enclosure

Additional Recommended attributes:

Attribute Key	Description	Example
bios_version	BIOS version
model	Descriptive model name
serial_number	Serial number
type	Type of the enclosure (useful for modular systems)	Computer, Storage, Switch
vendor	Vendor name

hw.fan. - Fan metrics

Description: Fan that keeps the air flowing to maintain the internal temperature of a computer

Name	Description	Units	Instrument Type (*)	Value Type	Attribute Key	Attribute Values
hw.fan.speed	Fan speed in revolutions per minute	rpm	Gauge	Int
hw.fan.speed.limit	Speed limit in rpm	rpm	Gauge	Int	limit_type (Recommended)	low.critical, low.degraded, max
hw.fan.speed_ratio	Fan speed expressed as a fraction of its maximum speed	1	Gauge	Double
hw.status	Operational status: 1 (true) or 0 (false) for each of the possible states		UpDownCounter	Int	state (Required)	ok, degraded, failed
					hw.type (Required)	fan

Additional Recommended attributes:

Attribute Key	Description	Example
sensor_location	Location of the fan in the computer enclosure	cpu0, ps1, INLET

hw.gpu. - GPU metrics

Description: Graphics Processing Unit (discrete)

Name	Description	Units	Instrument Type (*)	Value Type	Attribute Key	Attribute Values
hw.errors	Number of errors encountered by the GPU	{error}	Counter	Int64	hw.error.type (Recommended)	corrected, uncorrected
					hw.type (Required)	gpu
hw.gpu.io	Received and transmitted bytes by the GPU	By	Counter	Int64	direction (Required)	receive, transmit
hw.gpu.memory.limit	Size of the GPU memory	By	UpDownCounter	Int64
hw.gpu.memory.utilization	Fraction of GPU memory used	1	Gauge	Double
hw.gpu.memory.usage	GPU memory used	By	UpDownCounter	Int64
hw.gpu.power	GPU instantaneous power consumption in Watts	W	Gauge	Double
hw.gpu.utilization	Fraction of time spent in a specific task	1	Gauge	Double	task (Recommended)	decoder, encoder, general
hw.status	Operational status: 1 (true) or 0 (false) for each of the possible states		UpDownCounter	Int	state (Required)	ok, degraded, failed, predicted_failure
					hw.type (Required)	gpu

Additional Recommended attributes:

Attribute Key	Description	Example
driver_version	Driver for the controller
firmware_version	Firmware version
model	Descriptive model name
serial_number	Serial number
vendor	Vendor name

hw.logical_disk.- Logical disk metrics

Description: Storage extent presented as a physical disk by a disk controller to the operating system (e.g. a RAID 1 set made of 2 disks, and exposed as /dev/hdd0 by the controller).

Name	Description	Units	Instrument Type (*)	Value Type	Attribute Key	Attribute Values
hw.errors	Number of errors encountered on this logical disk	{error}	Counter	Int64	hw.type (Required)	logical_disk
hw.logical_disk.limit	Size of the logical disk	By	UpDownCounter	Int64
hw.logical_disk.usage	Logical disk space usage	By	UpDownCounter	Int64	state (Required)	used, free
hw.logical_disk.utilization	Logical disk space utilization as a fraction	1	Gauge	Double	state (Required)	used, free
hw.status	Operational status: 1 (true) or 0 (false) for each of the possible states		UpDownCounter	Int	state (Required)	ok, degraded, failed
					hw.type (Required)	logical_disk

Additional Recommended attributes:

Attribute Key	Description	Example
raid_level	RAID Level	RAID0+1

hw.memory. - Memory module metrics

Description: A memory module in a computer system.

Name	Description	Units	Instrument Type (*)	Value Type	Attribute Key	Attribute Values
hw.errors	Number of errors encountered on this memory module	{error}	Counter	Int64	hw.type (Required)	memory
hw.memory.size	Size of the memory module	By	UpDownCounter	Int64
hw.status	Operational status: 1 (true) or 0 (false) for each of the possible states		UpDownCounter	Int	state (Required)	ok, degraded, failed, predicted_failure
					hw.type (Required)	memory

Additional Recommended attributes:

Attribute Key	Description	Example
model	Descriptive model name
serial_number	Serial number
type	Type of the memory module	DDR5
vendor	Vendor name

hw.network. - Network adapter metrics

Description: A physical network interface, or a network interface controller (NIC), excluding software-based virtual adapters and loopbacks. For example, a physical network interface on a server, switch, router or firewall, an HBA, a fiber channel port or a Wi-Fi adapter.

Name	Description	Units	Instrument Type (*)	Value Type	Attribute Key	Attribute Values
hw.errors	Number of errors encountered by the network adapter	{error}	Counter	Int64	hw.error.type (Recommended)	zero_buffer_credit, crc, etc.
					hw.type (Required)	network
					direction (Recommended)	receive, transmit
hw.network.bandwidth.limit	Link speed	By/s	UpDownCounter	Int64
hw.network.bandwidth.utilization	Utilization of the network bandwidth as a fraction	1	Gauge	Double
hw.network.io	Received and transmitted network traffic in bytes	By	Counter	Int64	direction (Required)	receive, transmit
hw.network.packets	Received and transmitted network traffic in packets (or frames)	{packet}	Counter	Int64	direction (Required)	receive, transmit
hw.network.up	Link status: 1 (up) or 0 (down)		UpDownCounter	Int
hw.status	Operational status, regardless of the link status: 1 (true) or 0 (false) for each of the possible states		UpDownCounter	Int	state (Required)	ok, degraded, failed
					hw.type (Required)	network

Additional Recommended attributes:

Attribute Key	Description	Example
model	Descriptive model name
logical_addresses	Logical addresses of the adapter (e.g. IP address, or WWPN)	172.16.8.21, 57.11.193.42
physical_address	Physical address of the adapter (e.g. MAC address, or WWNN)	00-90-F5-E9-7B-36
serial_number	Serial number
vendor	Vendor name

hw.physical_disk.- Physical disk metrics

Description: Physical hard drive (HDD or SDD)

Name	Description	Units	Instrument Type (*)	Value Type	Attribute Key	Attribute Values
hw.errors	Number of errors encountered on this disk	{error}	Counter	Int64	hw.error.type (Recommended)	bad_sector, write, etc.
					hw.type (Required)	physical_disk
hw.physical_disk.endurance_utilization	Endurance remaining for this SSD disk	1	Gauge	Double	state (Required)	remaining
hw.physical_disk.size	Size of the disk	By	UpDownCounter	Int64
hw.physical_disk.smart	Value of the corresponding S.M.A.R.T. attribute	1	Gauge	Int	smart_attribute (Recommended)	Seek Error Rate, Spin Retry Count, etc.
hw.status	Operational status: 1 (true) or 0 (false) for each of the possible states		UpDownCounter	Int	state (Required)	ok, degraded, failed, predicted_failure
					hw.type (Required)	physical_disk

Additional Recommended attributes:

Attribute Key	Description	Example
firmware_version	Firmware version
model	Descriptive model name
serial_number	Serial number
type	Type of the disk	HDD, SSD, 10K
vendor	Vendor name

hw.power_supply. - Power supply metrics

Description: Power supply converting AC current to DC used by the motherboard and the GPUs

Name	Description	Units	Instrument Type (*)	Value Type	Attribute Key	Attribute Values
hw.power_supply.limit	Maximum power output of the power supply	W	UpDownCounter	Int64	limit_type (Recommended)	max, critical, throttled
hw.power_supply.utilization	Utilization of the power supply as a fraction of its maximum output	1	Gauge	Double
hw.status	Operational status: 1 (true) or 0 (false) for each of the possible states		UpDownCounter	Int	state (Required)	ok, degraded, failed
					hw.type (Required)	power_supply

Additional Recommended attributes:

Attribute Key	Description	Example
model	Descriptive model name
serial_number	Serial number
vendor	Vendor name

hw.tape_drive. - Tape drive metrics

Description: A tape drive in a computer or in a tape library (excluding virtual tape libraries)

Name	Description	Units	Instrument Type (*)	Value Type	Attribute Key	Attribute Values
hw.errors	Number of errors encountered by the tape drive	{error}	Counter	Int64	hw.error.type	read, write, mount, etc.
					hw.type (Required)	tape_drive
hw.tape_drive.operations	Operations performed by the tape drive	{operation}	Counter	Int64	type (Recommended)	mount, unmount, clean
hw.status	Operational status: 1 (true) or 0 (false) for each of the possible states		UpDownCounter	Int	state (Required)	ok, degraded, failed, needs_cleaning
					hw.type (Required)	tape_drive

Additional Recommended attributes:

Attribute Key	Description	Example
model	Descriptive model name
serial_number	Serial number
vendor	Vendor name

hw.temperature. - Temperature sensor metrics

Description: A temperature sensor, either numeric or discrete

Name	Description	Units	Instrument Type (*)	Value Type	Attribute Key	Attribute Values
hw.temperature	Temperature in degrees Celsius	Cel	Gauge	Double
hw.temperature.limit	Temperature limit in degrees Celsius	Cel	Gauge	Double	limit_type (Recommended)	low.critical, low.degraded, high.degraded, high.critical
hw.status	Whether the temperature is within normal range: 1 (true) or 0 (false) for each of the possible states		UpDownCounter	Int	state (Required)	ok, degraded, failed
					hw.type (Required)	temperature

Additional Recommended attributes:

Attribute Key	Description	Example
sensor_location	Location of the sensor	CPU0_DIE

hw.voltage. - Voltage sensor metrics

Description: A voltage sensor, either numeric or discrete

Name	Description	Units	Instrument Type (*)	Value Type	Attribute Key	Attribute Values
hw.voltage.limit	Voltage limit in Volts	V	Gauge	Double	limit_type (Recommended)	low.critical, low.degraded, high.degraded, high.critical
hw.voltage.nominal	Nominal (expected) voltage	V	Gauge	Double
hw.voltage	Voltage measured by the sensor	V	Gauge	Double
hw.status	Whether the voltage is within normal range: 1 (true) or 0 (false) for each of the possible states		UpDownCounter	Int	state (Required)	ok, degraded, failed
					hw.type (Required)	voltage

Additional Recommended attributes:

Attribute Key	Description	Example
sensor_location	Location of the sensor	PS0 V3_3