Node Exporter Metrics

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

Prometheus Node Exporter is a popular way to collect system level metrics from operating systems, such as CPU / Disk / Network / Process statistics. Fluent Bit 1.8.0 includes 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 initial release of Node Exporter Metrics contains a subset of collectors and metrics available from Prometheus Node Exporter and we plan to expand them over time.

Important note: Metrics collected with Node Exporter Metrics flow through a separate pipeline from logs and current filters do not operate on top of metrics.

This plugin is supported on Linux-based operating systems for the most part with macOS offering a reduced subset of metrics. The table below indicates which collector is supported on macOS.

Configuration

Key	Description	Default
scrape_interval	The rate at which metrics are collected from the host operating system	5 seconds
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. If a value greater than 0 is used then it overrides the global default otherwise the global default is used.	0 seconds
collector.cpufreq.scrape_interval	The rate in seconds at which cpufreq metrics are collected from the host operating system. If a value greater than 0 is used then it overrides the global default otherwise the global default is used.	0 seconds
collector.meminfo.scrape_interval	The rate in seconds at which meminfo metrics are collected from the host operating system. If a value greater than 0 is used then it overrides the global default otherwise the global default is used.	0 seconds
collector.diskstats.scrape_interval	The rate in seconds at which diskstats metrics are collected from the host operating system. If a value greater than 0 is used then it overrides the global default otherwise the global default is used.	0 seconds
collector.filesystem.scrape_interval	The rate in seconds at which filesystem metrics are collected from the host operating system. If a value greater than 0 is used then it overrides the global default otherwise the global default is used.	0 seconds
collector.uname.scrape_interval	The rate in seconds at which uname metrics are collected from the host operating system. If a value greater than 0 is used then it overrides the global default otherwise the global default is used.	0 seconds
collector.stat.scrape_interval	The rate in seconds at which stat metrics are collected from the host operating system. If a value greater than 0 is used then it overrides the global default otherwise the global default is used.	0 seconds
collector.time.scrape_interval	The rate in seconds at which time metrics are collected from the host operating system. If a value greater than 0 is used then it overrides the global default otherwise the global default is used.	0 seconds
collector.loadavg.scrape_interval	The rate in seconds at which loadavg metrics are collected from the host operating system. If a value greater than 0 is used then it overrides the global default otherwise the global default is used.	0 seconds
collector.vmstat.scrape_interval	The rate in seconds at which vmstat metrics are collected from the host operating system. If a value greater than 0 is used then it overrides the global default otherwise the global default is used.	0 seconds
collector.thermal_zone.scrape_interval	The rate in seconds at which thermal_zone metrics are collected from the host operating system. If a value greater than 0 is used then it overrides the global default otherwise the global default is used.	0 seconds
collector.filefd.scrape_interval	The rate in seconds at which filefd metrics are collected from the host operating system. If a value greater than 0 is used then it overrides the global default otherwise the global default is used.	0 seconds
collector.nvme.scrape_interval	The rate in seconds at which nvme metrics are collected from the host operating system. If a value greater than 0 is used then it overrides the global default otherwise the global default is used.	0 seconds
collector.processes.scrape_interval	The rate in seconds at which system level of process metrics are collected from the host operating system. If a value greater than 0 is used then it overrides the global default otherwise the global default is used.	0 seconds
metrics	To specify which metrics are collected from the host operating system. These metrics depend on /proc or /sys fs. 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 regex for the mount points to prevent collection of/ignore.	`^/(dev
filesystem.ignore_filesystem_type_regex	Specify the regex for the filesystem types to prevent collection of/ignore.	`^(autofs
diskstats.ignore_device_regex	Specify the regex for the diskstats to prevent collection of/ignore.	`^(ram
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	regex to determine which units are included in the metrics produced by the systemd collector	It is not applied unless explicitly set
systemd_exclude_pattern	regex to determine which units are excluded in the metrics produced by the systemd collector	`.+\.(automount

Note: The plugin top-level scrape_interval setting is the global default with any custom settings for individual scrape_intervals then overriding just 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.

The 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 5s and an override interval of 60s is used then the published metrics will be reported every 5s but for the specific collector they will stay the same for 60s until it is collected again. This feature aims to help with down-sampling when collecting metrics.

Collectors available

The following table describes the available collectors as part of this plugin. All of them are enabled by default and respects the original metrics name, descriptions, and types from Prometheus Exporter, so you can use your current dashboards without any compatibility problem.

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

Name	Description	OS	Version
cpu	Exposes CPU statistics.	Linux,macOS	v1.8
cpufreq	Exposes CPU frequency statistics.	Linux	v1.8
diskstats	Exposes disk I/O statistics.	Linux,macOS	v1.8
filefd	Exposes file descriptor statistics from /proc/sys/fs/file-nr.	Linux	v1.8.2
filesystem	Exposes filesystem statistics from /proc/*/mounts.	Linux	v2.0.9
loadavg	Exposes load average.	Linux,macOS	v1.8
meminfo	Exposes memory statistics.	Linux,macOS	v1.8
netdev	Exposes network interface statistics such as bytes transferred.	Linux,macOS	v1.8.2
stat	Exposes various statistics from /proc/stat. This includes boot time, forks, and interruptions.	Linux	v1.8
time	Exposes the current system time.	Linux	v1.8
uname	Exposes system information as provided by the uname system call.	Linux,macOS	v1.8
vmstat	Exposes statistics from /proc/vmstat.	Linux	v1.8.2
systemd collector	Exposes statistics from systemd.	Linux	v2.1.3
thermal_zone	Expose thermal statistics from /sys/class/thermal/thermal_zone/*	Linux	v2.2.1
nvme	Exposes nvme statistics from /proc.	Linux	v2.2.0
processes	Exposes processes statistics from /proc.	Linux	v2.2.0

Threading

This input always runs in its own thread.

Getting Started

Simple Configuration File

In the following configuration file, the input plugin _node_exporter_metrics collects _metrics every 2 seconds and exposes them through our Prometheus Exporter output plugin on HTTP/TCP port 2021.

fluent-bit.conf

# 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

[INPUT]
    name            node_exporter_metrics
    tag             node_metrics
    scrape_interval 2

[OUTPUT]
    name            prometheus_exporter
    match           node_metrics
    host            0.0.0.0
    port            2021

fluent-bit.yaml

# 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 + Prometheus + Grafana

If you like dashboards for monitoring, Grafana is one of the preferred options. In our Fluent Bit source code repository, we have pushed a simple **docker-compose **example. Steps:

Get a copy of Fluent Bit source code

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

Start the service and view your Dashboard

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

Now open your browser in the address http://127.0.0.1:3000. When asked for the credentials to access Grafana, just use the **admin **username and admin password.

Note that by default Grafana dashboard plots the data from the last 24 hours, so just change it to Last 5 minutes to see the recent data being collected.

Stop the Service

docker-compose down

Enhancement Requests

Our current plugin implements a sub-set of the available collectors in the original Prometheus Node Exporter, if you would like that we prioritize a specific collector please open a Github issue by using the following template: - in_node_exporter_metrics