OpenTelemetry Host Metrics receiver

hostmetricsreceiver is an OpenTelemetry Collector plugin that gathers various metrics about the host system, for example, CPU, RAM, disk metrics and other system-level metrics.

By collecting and analyzing host metrics, you can gain insights into the performance and health of your host systems and identify potential issues or bottlenecks that may be impacting the overall performance of your applications and services.

• What is OpenTelemetry Collector?
• Host Metrics
• Filesystem metrics
• Process metrics
• Container host metrics

What is OpenTelemetry Collector?

OpenTelemetry Collector is an agent that pulls telemetry data from systems you want to monitor and sends it to tracing tools using the OpenTelemetry protocol (OTLP).

You can use OpenTelemetry Collector to monitor host metrics, PostgreSQL, MySQL, Redis, and more.

Host Metrics

To start collecting host metrics, you need to install Collector on each system you want to monitor and add the following lines to the Collector config:

processors:
  resourcedetection:
    detectors: [env, system]
  cumulativetodelta:

receivers:
  hostmetrics:
    collection_interval: 10s
    scrapers:
      # CPU utilization metrics
      cpu:
      # Disk I/O metrics
      disk:
      # File System utilization metrics
      filesystem:
      # CPU load metrics
      load:
      # Memory utilization metrics
      memory:
      # Network interface I/O metrics & TCP connection metrics
      network:
      # Paging/Swap space utilization and I/O metrics
      paging:

service:
  pipelines:
    metrics:
      receivers: [otlp, hostmetrics]
      processors: [cumulativetodelta, batch, resourcedetection]
      exporters: [otlp/uptrace]

If you need to configure otlp/uptrace exporter, see Sending data from Otel Collector to Uptrace.

Filesystem metrics

If you are using unusual filesystems, you may want to configure filesystem receiver more thoroughly, for example, to scrape only supported filesystem types and avoid warnings:

receivers:
  hostmetrics:
    collection_interval: 10s
    scrapers:
      cpu:
      disk:
      load:
      filesystem:
        include_fs_types:
          match_type: strict
          fs_types: [ext3, ext4]
      memory:
      network:
      paging:

Process metrics

To collect per process CPU, Memory, and Disk I/O metrics, you need to enable the respective scrapers:

receivers:
  hostmetrics:
    collection_interval: 10s
    scrapers:
      # Process count metrics
      process:
      # Per process CPU, Memory, and Disk I/O metrics
      processes:

Those scrapers are disabled by default, because they require running OpenTelemetry Collector with elevated permissions in order to access information about other processes.

On Linux, you can achieve that by running otelcol-contrib under root user:

# /lib/systemd/system/otelcol-contrib.service

User=root
Group=root

Or using sudo to start the process:

# /lib/systemd/system/otelcol-contrib.service

ExecStart=sudo /usr/bin/otelcol-contrib $OTELCOL_OPTIONS

Container host metrics

On Linux, OpenTelemetry collects metrics from the Linux system directories. To collect metrics about the host system and not the container, you can mount the host filesystem when running the container:

# mount the entire filesystem
docker run -v /:/hostfs ...

# or mount only parts you need
docker run -v /proc:/hostfs/proc ...

Then configure root_path so the hostmetrics receiver knows where the root filesystem is:

receivers:
  hostmetrics:
    root_path: /hostfs