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Node Exporter Metrics

A plugin based on Prometheus Node Exporter to collect system and host level metrics

Prometheus Node exporter is a popular way to collect system level metrics from operating systems, such as CPU, disk, network, and process statistics. Fluent Bit includes a node exporter metrics plugin that builds off the Prometheus design to collect system level metrics without having to manage two separate processes or agents.

The Node exporter metrics plugin contains a subset of collectors and metrics available from Prometheus Node exporter.

Metrics collected with Node Exporter Metrics flow through a separate pipeline from logs and current filters don't operate on top of metrics.

This plugin is generally supported on Linux-based operating systems, with macOS offering a reduced subset of metrics.

Configuration

scrape_interval sets the default for all scrapes. To set granular scrape intervals, set the specific interval. For example, collector.cpu.scrape_interval. When using a granular scrape interval, if a value greater than 0 is used, it overrides the global default. Otherwise the global default is used.

The plugin top-level scrape_interval setting is the global default. Any custom settings for individual scrape_intervals override that specific metric scraping interval.

Each collector.xxx.scrape_interval option only overrides the interval for that specific collector and updates the associated set of provided metrics.

Overridden intervals only change the collection interval, not the interval for publishing the metrics which is taken from the global setting.

For example, if the global interval is set to 5 and an override interval of 60 is used, the published metrics will be reported every five seconds. However, the specific collector will stay the same for 60 seconds until it's collected again.

This helps with downsampling when collecting metrics.

Key
Description
Default

scrape_interval

The rate in seconds at which metrics are collected from the host operating system.

5

path.procfs

The mount point used to collect process information and metrics.

/proc/

path.sysfs

The path in the filesystem used to collect system metrics.

/sys/

collector.cpu.scrape_interval

The rate in seconds at which cpu metrics are collected from the host operating system.

0

collector.cpufreq.scrape_interval

The rate in seconds at which cpufreq metrics are collected from the host operating system.

0

collector.meminfo.scrape_interval

The rate in seconds at which meminfo metrics are collected from the host operating system.

0

collector.diskstats.scrape_interval

The rate in seconds at which diskstats metrics are collected from the host operating system.

0

collector.filesystem.scrape_interval

The rate in seconds at which filesystem metrics are collected from the host operating system.

0

collector.uname.scrape_interval

The rate in seconds at which uname metrics are collected from the host operating system.

0

collector.stat.scrape_interval

The rate in seconds at which stat metrics are collected from the host operating system.

0

collector.time.scrape_interval

The rate in seconds at which time metrics are collected from the host operating system.

0

collector.loadavg.scrape_interval

The rate in seconds at which loadavg metrics are collected from the host operating system.

0

collector.vmstat.scrape_interval

The rate in seconds at which vmstat metrics are collected from the host operating system.

0

collector.thermal_zone.scrape_interval

The rate in seconds at which thermal_zone metrics are collected from the host operating system.

0

collector.filefd.scrape_interval

The rate in seconds at which filefd metrics are collected from the host operating system.

0

collector.nvme.scrape_interval

The rate in seconds at which nvme metrics are collected from the host operating system.

0

collector.processes.scrape_interval

The rate in seconds at which system level process metrics are collected from the host operating system.

0

metrics

Specify which metrics are collected from the host operating system. These metrics depend on /procfs or /sysfs. The actual values of metrics will be read from /proc or /sys when needed. cpu, cpufreq, meminfo, diskstats, filesystem, stat, loadavg, vmstat, netdev, and filefd depend on procfs. cpufreq metrics depend on sysfs.

"cpu,cpufreq,meminfo,diskstats,filesystem,uname,stat,time,loadavg,vmstat,netdev,filefd"

filesystem.ignore_mount_point_regex

Specify the regular expression for the mount points to prevent collection of/ignore.

^/(dev|proc|run/credentials/.+|sys|var/lib/docker/.+|var/lib/containers/storage/.+)($|/)

filesystem.ignore_filesystem_type_regex

Specify the regular expression for the filesystem types to prevent collection of or ignore.

^(autofs|binfmt_misc|bpf|cgroup2?|configfs|debugfs|devpts|devtmpfs|fusectl|hugetlbfs|iso9660|mqueue|nsfs|overlay|proc|procfs|pstore|rpc_pipefs|securityfs|selinuxfs|squashfs|sysfs|tracefs)$

diskstats.ignore_device_regex

Specify the regular expression for the diskstats to prevent collection of/ignore.

^(ram|loop|fd|(h|s|v|xv)d[a-z]|nvme\\d+n\\d+p)\\d+$

systemd_service_restart_metrics

Determines if the collector will include service restart metrics.

false

systemd_unit_start_time_metrics

Determines if the collector will include unit start time metrics.

false

systemd_include_service_task_metrics

Determines if the collector will include service task metrics.

false

systemd_include_pattern

Regular expression to determine which units are included in the metrics produced by the systemd collector.

Not applied unless explicitly set.

systemd_exclude_pattern

Regular expression to determine which units are excluded in the metrics produced by the systemd collector.

.+\\.(automount|device|mount|scope|slice)"

Collectors available

The following table describes the available collectors as part of this plugin. They're enabled by default and respect the original metrics name, descriptions, and types from Prometheus Exporter. You can use your current dashboards without any compatibility problem.

The Version column specifies the Fluent Bit version where the collector is available.

Name
Description
Operating system
Version

cpu

Exposes CPU statistics.

Linux, macOS

1.8

cpufreq

Exposes CPU frequency statistics.

Linux

1.8

diskstats

Exposes disk I/O statistics.

Linux, macOS

1.8

filefd

Exposes file descriptor statistics from /proc/sys/fs/file-nr.

Linux

1.8.2

filesystem

Exposes filesystem statistics from /proc/*/mounts.

Linux

2.0.9

loadavg

Exposes load average.

Linux, macOS

1.8

meminfo

Exposes memory statistics.

Linux, macOS

1.8

netdev

Exposes network interface statistics such as bytes transferred.

Linux, macOS

1.8.2

stat

Exposes various statistics from /proc/stat. This includes boot time, forks, and interruptions.

Linux

1.8

time

Exposes the current system time.

Linux

v1.8

uname

Exposes system information as provided by the uname system call.

Linux, macOS

1.8

vmstat

Exposes statistics from /proc/vmstat.

Linux

1.8.2

systemd collector

Exposes statistics from systemd.

Linux

2.1.3

thermal_zone

Expose thermal statistics from /sys/class/thermal/thermal_zone/*

Linux

2.2.1

nvme

Exposes nvme statistics from /proc.

Linux

2.2.0

processes

Exposes processes statistics from /proc.

Linux

2.2.0

Threading

This input always runs in its own thread.

Get started

Configuration file

In the following configuration file, the input plugin node_exporter_metrics collects metrics every two seconds and exposes them through the Prometheus Exporter output plugin on HTTP/TCP port 2021.

# Node Exporter Metrics + Prometheus Exporter
# -------------------------------------------
# The following example collect host metrics on Linux and expose
# them through a Prometheus HTTP end-point.
#
# After starting the service try it with:
#
# $ curl http://127.0.0.1:2021/metrics
#
service:
    flush: 1
    log_level: info
pipeline:
    inputs:
        - name: node_exporter_metrics
          tag:  node_metrics
          scrape_interval: 2
    outputs:
        - name: prometheus_exporter
          match: node_metrics
          host: 0.0.0.0
          port: 2021

You can test the expose of the metrics by using curl:

curl http://127.0.0.1:2021/metrics

Container to collect host metrics

When deploying Fluent Bit in a container you will need to specify additional settings to ensure that Fluent Bit has access to the host operating system. The following Docker command deploys Fluent Bit with specific mount paths and settings enabled to ensure that Fluent Bit can collect from the host. These are then exposed over port 2021.

docker run -ti -v /proc:/host/proc \
               -v /sys:/host/sys   \
               -p 2021:2021        \
               fluent/fluent-bit:1.8.0 \
               /fluent-bit/bin/fluent-bit \
                         -i node_exporter_metrics -p path.procfs=/host/proc -p path.sysfs=/host/sys \
                         -o prometheus_exporter -p "add_label=host $HOSTNAME" \
                         -f 1

Fluent Bit with Prometheus and Grafana

If you use dashboards for monitoring, Grafana is one option. The Fluent Bit source code repository contains a docker-compose example.

  1. Download the Fluent Bit source code:

    git clone https://github.com/fluent/fluent-bit
cd fluent-bit/docker_compose/node-exporter-dashboard/

  2. Start the service and view your dashboard:

    docker-compose up --force-recreate -d --build

  3. Open your browser and use the address http://127.0.0.1:3000.

  4. When asked for the credentials to access Grafana, use admin for the username and password. See Sign in to Grafana.

An example Grafana dashboard

By default, Grafana dashboard plots the data from the last 24 hours. Change it to Last 5 minutes to see the recent data being collected.

Stop the Service

docker-compose down

Enhancement requests

The plugin implements a subset of the available collectors in the original Prometheus Node exporter. If you would like a specific collector prioritized, open a GitHub issue by using the following template:

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