Network I/O metrics

The Network I/O metrics (netif) input plugin gathers network traffic information of the running system at regular intervals, and reports them. This plugin is available only for Linux.

The Network I/O metrics plugin creates metrics that are log-based, such as JSON payload. For Prometheus-based metrics, see the Node Exporter metrics input plugin.

Metrics reported

The following table describes the metrics generated by the plugin. Metric names are prefixed with the interface name (for example, eth0):

Key	Description
{interface}.rx.bytes	Number of bytes received on the interface.
{interface}.rx.packets	Number of packets received on the interface.
{interface}.rx.errors	Number of receive errors on the interface.
{interface}.tx.bytes	Number of bytes transmitted on the interface.
{interface}.tx.packets	Number of packets transmitted on the interface.
{interface}.tx.errors	Number of transmit errors on the interface.

Configuration parameters

The plugin supports the following configuration parameters:

Key	Description	Default
interface	Specify the network interface to monitor. For example, eth0.	none
interval_nsec	Polling interval in nanoseconds.	0
interval_sec	Polling interval in seconds.	1
test_at_init	If true, test if the network interface is valid at initialization.	false
threaded	Indicates whether to run this input in its own thread.	false
verbose	If true, gather metrics precisely.	false

Get started

To monitor network traffic from your system, you can run the plugin from the command line or through the configuration file.

Command line

Run Fluent Bit using a command similar to the following:

fluent-bit -i netif -p interface=eth0 -o stdout

Which returns output similar to the following:

...
[0] netif.0: [1499524459.001698260, {"eth0.rx.bytes"=>89769869, "eth0.rx.packets"=>73357, "eth0.rx.errors"=>0, "eth0.tx.bytes"=>4256474, "eth0.tx.packets"=>24293, "eth0.tx.errors"=>0}]
[1] netif.0: [1499524460.002541885, {"eth0.rx.bytes"=>98, "eth0.rx.packets"=>1, "eth0.rx.errors"=>0, "eth0.tx.bytes"=>98, "eth0.tx.packets"=>1, "eth0.tx.errors"=>0}]
[2] netif.0: [1499524461.001142161, {"eth0.rx.bytes"=>98, "eth0.rx.packets"=>1, "eth0.rx.errors"=>0, "eth0.tx.bytes"=>98, "eth0.tx.packets"=>1, "eth0.tx.errors"=>0}]
[3] netif.0: [1499524462.002612971, {"eth0.rx.bytes"=>98, "eth0.rx.packets"=>1, "eth0.rx.errors"=>0, "eth0.tx.bytes"=>98, "eth0.tx.packets"=>1, "eth0.tx.errors"=>0}]
...

Configuration file

In your main configuration file append the following:

fluent-bit.yaml

pipeline:
  inputs:
    - name: netif
      tag: netif
      interface: eth0
      interval_sec: 1
      interval_nsec: 0
      verbose: false
      test_at_init: false

  outputs:
    - name: stdout
      match: '*'

fluent-bit.conf

Total interval (sec) = interval_sec + (interval_nsec / 1000000000)

For example: 1.5s = 1s + 500000000ns