groups:
  # system.cpu.* metrics
  - id: metric.system.cpu.time
    type: metric
    metric_name: system.cpu.time
    stability: experimental
    brief: "Seconds each logical CPU spent on each mode"
    instrument: counter
    unit: "s"
    attributes:
      - ref: cpu.mode
        brief: "The CPU mode for this data point. A system's CPU SHOULD be characterized *either* by data points with no `mode` labels, *or only* data points with `mode` labels."
        note: "Following states SHOULD be used: `user`, `system`, `nice`, `idle`, `iowait`, `interrupt`, `steal`"
      - ref: system.cpu.logical_number

  - id: metric.system.cpu.utilization
    type: metric
    metric_name: system.cpu.utilization
    stability: experimental
    brief: "Difference in system.cpu.time since the last measurement, divided by the elapsed time and number of logical CPUs"
    instrument: gauge
    unit: "1"
    attributes:
      - ref: cpu.mode
        brief: "The CPU mode for this data point. A system's CPU SHOULD be characterized *either* by data points with no `mode` labels, *or only* data points with `mode` labels."
        note: "Following modes SHOULD be used: `user`, `system`, `nice`, `idle`, `iowait`, `interrupt`, `steal`"
      - ref: system.cpu.logical_number

  - id: metric.system.cpu.frequency
    type: metric
    metric_name: system.cpu.frequency
    stability: experimental
    brief: "Reports the current frequency of the CPU in Hz"
    instrument: gauge
    unit: "{Hz}"
    attributes:
      - ref: system.cpu.logical_number

  - id: metric.system.cpu.physical.count
    type: metric
    metric_name: system.cpu.physical.count
    stability: experimental
    brief: "Reports the number of actual physical processor cores on the hardware"
    instrument: updowncounter
    unit: "{cpu}"
    attributes: []

  - id: metric.system.cpu.logical.count
    type: metric
    metric_name: system.cpu.logical.count
    stability: experimental
    brief: "Reports the number of logical (virtual) processor cores created by the operating system to manage multitasking"
    instrument: updowncounter
    unit: "{cpu}"
    attributes: []

  # system.memory.* metrics
  - id: metric.system.memory.usage
    type: metric
    metric_name: system.memory.usage
    stability: experimental
    brief: "Reports memory in use by state."
    note: |
      The sum over all `system.memory.state` values SHOULD equal the total memory
      available on the system, that is `system.memory.limit`.
    instrument: updowncounter
    unit: "By"
    attributes:
      - ref: system.memory.state

  - id: metric.system.memory.limit
    type: metric
    metric_name: system.memory.limit
    stability: experimental
    brief: "Total memory available in the system."
    note: |
      Its value SHOULD equal the sum of `system.memory.state` over all states.
    instrument: updowncounter
    unit: "By"
    attributes: []

  - id: metric.system.memory.shared
    type: metric
    metric_name: system.memory.shared
    stability: experimental
    brief: "Shared memory used (mostly by tmpfs)."
    note: |
      Equivalent of `shared` from [`free` command](https://man7.org/linux/man-pages/man1/free.1.html) or
      `Shmem` from [`/proc/meminfo`](https://man7.org/linux/man-pages/man5/proc.5.html)"
    instrument: updowncounter
    unit: "By"

  - id: metric.system.memory.utilization
    type: metric
    metric_name: system.memory.utilization
    stability: experimental
    brief: ""
    instrument: gauge
    unit: "1"
    attributes:
      - ref: system.memory.state

  # system.paging.* metrics
  - id: metric.system.paging.usage
    type: metric
    metric_name: system.paging.usage
    stability: experimental
    brief: "Unix swap or windows pagefile usage"
    instrument: updowncounter
    unit: "By"
    attributes:
      - ref: system.paging.state

  - id: metric.system.paging.utilization
    type: metric
    metric_name: system.paging.utilization
    stability: experimental
    brief: ""
    instrument: gauge
    unit: "1"
    attributes:
      - ref: system.paging.state

  - id: metric.system.paging.faults
    type: metric
    metric_name: system.paging.faults
    stability: experimental
    brief: ""
    instrument: counter
    unit: "{fault}"
    attributes:
      - ref: system.paging.type

  - id: metric.system.paging.operations
    type: metric
    metric_name: system.paging.operations
    stability: experimental
    brief: ""
    instrument: counter
    unit: "{operation}"
    attributes:
      - ref: system.paging.type
      - ref: system.paging.direction

  # system.disk.* metrics
  - id: metric.system.disk.io
    type: metric
    metric_name: system.disk.io
    stability: experimental
    brief: ""
    instrument: counter
    unit: "By"
    attributes:
      - ref: system.device
      - ref: disk.io.direction

  - id: metric.system.disk.operations
    type: metric
    metric_name: system.disk.operations
    stability: experimental
    brief: ""
    instrument: counter
    unit: "{operation}"
    attributes:
      - ref: system.device
      - ref: disk.io.direction

  - id: metric.system.disk.io_time
    type: metric
    metric_name: system.disk.io_time
    stability: experimental
    brief: "Time disk spent activated"
    instrument: counter
    unit: "s"
    note: |
       The real elapsed time ("wall clock") used in the I/O path (time from operations running in parallel are not counted). Measured as:

       - Linux: Field 13 from [procfs-diskstats](https://www.kernel.org/doc/Documentation/ABI/testing/procfs-diskstats)
       - Windows: The complement of
         ["Disk\% Idle Time"](https://learn.microsoft.com/archive/blogs/askcore/windows-performance-monitor-disk-counters-explained#windows-performance-monitor-disk-counters-explained)
         performance counter: `uptime * (100 - "Disk\% Idle Time") / 100`
    attributes:
      - ref: system.device

  - id: metric.system.disk.operation_time
    type: metric
    metric_name: system.disk.operation_time
    stability: experimental
    brief: "Sum of the time each operation took to complete"
    instrument: counter
    unit: "s"
    note: |
       Because it is the sum of time each request took, parallel-issued requests each contribute to make the count grow. Measured as:

       - Linux: Fields 7 & 11 from [procfs-diskstats](https://www.kernel.org/doc/Documentation/ABI/testing/procfs-diskstats)
       - Windows: "Avg. Disk sec/Read" perf counter multiplied by "Disk Reads/sec" perf counter (similar for Writes)
    attributes:
      - ref: system.device
      - ref: disk.io.direction

  - id: metric.system.disk.merged
    type: metric
    metric_name: system.disk.merged
    stability: experimental
    brief: ""
    instrument: counter
    unit: "{operation}"
    attributes:
      - ref: system.device
      - ref: disk.io.direction

  # system.filesystem.* metrics
  - id: metric.system.filesystem.usage
    type: metric
    metric_name: system.filesystem.usage
    stability: experimental
    brief: ""
    instrument: updowncounter
    unit: "By"
    attributes:
      - ref: system.device
      - ref: system.filesystem.state
      - ref: system.filesystem.type
      - ref: system.filesystem.mode
      - ref: system.filesystem.mountpoint

  - id: metric.system.filesystem.utilization
    type: metric
    metric_name: system.filesystem.utilization
    stability: experimental
    brief: ""
    instrument: gauge
    unit: "1"
    attributes:
      - ref: system.device
      - ref: system.filesystem.state
      - ref: system.filesystem.type
      - ref: system.filesystem.mode
      - ref: system.filesystem.mountpoint

  # system.network.* metrics
  - id: metric.system.network.dropped
    type: metric
    metric_name: system.network.dropped
    stability: experimental
    brief: "Count of packets that are dropped or discarded even though there was no error"
    instrument: counter
    unit: "{packet}"
    note: |
      Measured as:

      - Linux: the `drop` column in `/proc/dev/net` ([source](https://web.archive.org/web/20180321091318/http://www.onlamp.com/pub/a/linux/2000/11/16/LinuxAdmin.html))
      - Windows: [`InDiscards`/`OutDiscards`](https://docs.microsoft.com/windows/win32/api/netioapi/ns-netioapi-mib_if_row2)
        from [`GetIfEntry2`](https://docs.microsoft.com/windows/win32/api/netioapi/nf-netioapi-getifentry2)
    attributes:
      - ref: system.device
      - ref: network.io.direction

  - id: metric.system.network.packets
    type: metric
    metric_name: system.network.packets
    stability: experimental
    brief: ""
    instrument: counter
    unit: "{packet}"
    attributes:
      - ref: system.device
      - ref: network.io.direction

  - id: metric.system.network.errors
    type: metric
    metric_name: system.network.errors
    stability: experimental
    brief: "Count of network errors detected"
    instrument: counter
    unit: "{error}"
    note: |
      Measured as:

      - Linux: the `errs` column in `/proc/dev/net` ([source](https://web.archive.org/web/20180321091318/http://www.onlamp.com/pub/a/linux/2000/11/16/LinuxAdmin.html)).
      - Windows: [`InErrors`/`OutErrors`](https://docs.microsoft.com/windows/win32/api/netioapi/ns-netioapi-mib_if_row2)
        from [`GetIfEntry2`](https://docs.microsoft.com/windows/win32/api/netioapi/nf-netioapi-getifentry2).
    attributes:
      - ref: system.device
      - ref: network.io.direction

  - id: metric.system.network.io
    type: metric
    metric_name: system.network.io
    stability: experimental
    brief: ""
    instrument: counter
    unit: "By"
    attributes:
      - ref: system.device
      - ref: network.io.direction

  - id: metric.system.network.connections
    type: metric
    metric_name: system.network.connections
    stability: experimental
    brief: ""
    instrument: updowncounter
    unit: "{connection}"
    attributes:
      - ref: system.device
      - ref: system.network.state
      - ref: network.transport

  # system.process.* metrics
  - id: metric.system.process.count
    type: metric
    metric_name: system.process.count
    stability: experimental
    brief: "Total number of processes in each state"
    instrument: updowncounter
    unit: "{process}"
    attributes:
      - ref: system.process.status

  - id: metric.system.process.created
    type: metric
    metric_name: system.process.created
    stability: experimental
    brief: "Total number of processes created over uptime of the host"
    instrument: counter
    unit: "{process}"
    attributes: []

  # system.linux.* metrics
  - id: metric.system.linux.memory.available
    type: metric
    metric_name: system.linux.memory.available
    stability: experimental
    brief: "An estimate of how much memory is available for starting new applications, without causing swapping"
    note: |
      This is an alternative to `system.memory.usage` metric with `state=free`.
      Linux starting from 3.14 exports "available" memory. It takes "free" memory as a baseline, and then factors in kernel-specific values.
      This is supposed to be more accurate than just "free" memory.
      For reference, see the calculations [here](https://superuser.com/a/980821).
      See also `MemAvailable` in [/proc/meminfo](https://man7.org/linux/man-pages/man5/proc.5.html).
    instrument: updowncounter
    unit: "By"
    attributes: []