# Host Metrics Receiver

The Host Metrics receiver generates metrics about the host system scraped
from various sources. This is intended to be used when the collector is
deployed as an agent.

Supported pipeline types: metrics

## Getting Started

The collection interval and the categories of metrics to be scraped can be
configured:

```yaml
hostmetrics:
  collection_interval: <duration> # default = 1m
  scrapers:
    <scraper1>:
    <scraper2>:
    ...
```

The available scrapers are:

| Scraper    | Supported OSs                | Description                                            |
|------------|------------------------------|--------------------------------------------------------|
| cpu        | All except Mac<sup>[1]</sup> | CPU utilization metrics                                |
| disk       | All except Mac<sup>[1]</sup> | Disk I/O metrics                                       |
| load       | All                          | CPU load metrics                                       |
| filesystem | All                          | File System utilization metrics                        |
| memory     | All                          | Memory utilization metrics                             |
| network    | All                          | Network interface I/O metrics & TCP connection metrics |
| paging     | All                          | Paging/Swap space utilization and I/O metrics
| processes  | Linux                        | Process count metrics                                  |
| process    | Linux & Windows              | Per process CPU, Memory, and Disk I/O metrics          |

### Notes

<sup>[1]</sup> Not supported on Mac when compiled without cgo which is the default.

Several scrapers support additional configuration:

### Disk

```yaml
disk:
  <include|exclude>:
    devices: [ <device name>, ... ]
    match_type: <strict|regexp>
```

### File System

```yaml
filesystem:
  <include_devices|exclude_devices>:
    devices: [ <device name>, ... ]
    match_type: <strict|regexp>
  <include_fs_types|exclude_fs_types>:
    fs_types: [ <filesystem type>, ... ]
    match_type: <strict|regexp>
  <include_mount_points|exclude_mount_points>:
    mount_points: [ <mount point>, ... ]
    match_type: <strict|regexp>
```

### Network

```yaml
network:
  <include|exclude>:
    interfaces: [ <interface name>, ... ]
    match_type: <strict|regexp>
```

### Process

```yaml
process:
  disk:
    <include|exclude>:
      names: [ <process name>, ... ]
      match_type: <strict|regexp>
```

## Advanced Configuration

### Filtering

If you are only interested in a subset of metrics from a particular source,
it is recommended you use this receiver with the
[Filter Processor](https://github.com/open-telemetry/opentelemetry-collector/tree/master/processor/filterprocessor).

### Different Frequencies

If you would like to scrape some metrics at a different frequency than others,
you can configure multiple `hostmetrics` receivers with different
`collection_interval` values. For example:

```yaml
receivers:
  hostmetrics:
    collection_interval: 30s
    scrapers:
      cpu:
      memory:

  hostmetrics/disk:
    collection_interval: 1m
    scrapers:
      disk:
      filesystem:

service:
  pipelines:
    metrics:
      receivers: [hostmetrics, hostmetrics/disk]
```
