Host

type: host

Description: A host is defined as a computing instance. For example, physical servers, virtual machines, switches or disk array.

The host.* namespace SHOULD be exclusively used to capture resource attributes. To report host metrics, the system.* namespace SHOULD be used.

Attribute	Type	Description	Examples	Requirement Level
`host.arch`	string	The CPU architecture the host system is running on.	`amd64`	Recommended
`host.id`	string	Unique host ID. For Cloud, this must be the instance_id assigned by the cloud provider. For non-containerized systems, this should be the `machine-id`. See the table below for the sources to use to determine the `machine-id` based on operating system.	`fdbf79e8af94cb7f9e8df36789187052`	Recommended
`host.image.id`	string	VM image ID or host OS image ID. For Cloud, this value is from the provider.	`ami-07b06b442921831e5`	Recommended
`host.image.name`	string	Name of the VM image or OS install the host was instantiated from.	`infra-ami-eks-worker-node-7d4ec78312`; `CentOS-8-x86_64-1905`	Recommended
`host.image.version`	string	The version string of the VM image or host OS as defined in Version Attributes.	`0.1`	Recommended
`host.ip`	string[]	Available IP addresses of the host, excluding loopback interfaces. [1]	`[192.168.1.140, fe80::abc2:4a28:737a:609e]`	Opt-In
`host.mac`	string[]	Available MAC addresses of the host, excluding loopback interfaces. [2]	`[AC-DE-48-23-45-67, AC-DE-48-23-45-67-01-9F]`	Opt-In
`host.name`	string	Name of the host. On Unix systems, it may contain what the hostname command returns, or the fully qualified hostname, or another name specified by the user.	`opentelemetry-test`	Recommended
`host.type`	string	Type of host. For Cloud, this must be the machine type.	`n1-standard-1`	Recommended

[1]: IPv4 Addresses MUST be specified in dotted-quad notation. IPv6 addresses MUST be specified in the RFC 5952 format.

[2]: MAC Addresses MUST be represented in IEEE RA hexadecimal form: as hyphen-separated octets in uppercase hexadecimal form from most to least significant.

host.arch has the following list of well-known values. If one of them applies, then the respective value MUST be used, otherwise a custom value MAY be used.

Value	Description
`amd64`	AMD64
`arm32`	ARM32
`arm64`	ARM64
`ia64`	Itanium
`ppc32`	32-bit PowerPC
`ppc64`	64-bit PowerPC
`s390x`	IBM z/Architecture
`x86`	32-bit x86

type: host.cpu

Attribute	Type	Description	Examples	Requirement Level
`host.cpu.cache.l2.size`	int	The amount of level 2 memory cache available to the processor (in Bytes).	`12288000`	Opt-In
`host.cpu.family`	string	Family or generation of the CPU.	`6`; `PA-RISC 1.1e`	Opt-In
`host.cpu.model.id`	string	Model identifier. It provides more granular information about the CPU, distinguishing it from other CPUs within the same family.	`6`; `9000/778/B180L`	Opt-In
`host.cpu.model.name`	string	Model designation of the processor.	`11th Gen Intel(R) Core(TM) i7-1185G7 @ 3.00GHz`	Opt-In
`host.cpu.stepping`	int	Stepping or core revisions.	`1`	Opt-In
`host.cpu.vendor.id`	string	Processor manufacturer identifier. A maximum 12-character string. [1]	`GenuineIntel`	Opt-In

[1]: CPUID command returns the vendor ID string in EBX, EDX and ECX registers. Writing these to memory in this order results in a 12-character string.

Collecting host.id from non-containerized systems

Non-privileged Machine ID Lookup

When collecting host.id for non-containerized systems non-privileged lookups of the machine id are preferred. SDK detector implementations MUST use the sources listed below to obtain the machine id.

OS	Primary	Fallback
Linux	contents of `/etc/machine-id`	contents of `/var/lib/dbus/machine-id`
BSD	contents of `/etc/hostid`	output of `kenv -q smbios.system.uuid`
MacOS	`IOPlatformUUID` line from the output of `ioreg -rd1 -c "IOPlatformExpertDevice"`	-
Windows	`MachineGuid` from registry `HKEY_LOCAL_MACHINE\\SOFTWARE\\Microsoft\\Cryptography`	-

Privileged Machine ID Lookup

The host.id can be looked up using privileged sources. For example, Linux systems can use the output of dmidecode -t system, dmidecode -t baseboard, dmidecode -t chassis, or read the corresponding data from the filesystem (e.g. cat /sys/devices/virtual/dmi/id/product_id, cat /sys/devices/virtual/dmi/id/product_uuid, etc), however, SDK resource detector implementations MUST not collect host.id from privileged sources. If privileged lookup of host.id is required, the value should be injected via the OTEL_RESOURCE_ATTRIBUTES environment variable.