The cpu input plugin, measures the CPU usage of a process or the whole system by default (considering per CPU core). It reports values in percentage unit for every interval of time set. At the moment this plugin is only available for Linux.

The following tables describes the information generated by the plugin. The keys below represent the data used by the overall system, all values associated to the keys are in a percentage unit (0 to 100%):

The CPU metrics plugin creates metrics that are log-based, such as JSON payload. For Prometheus-based metrics, see the Node Exporter Metrics input plugin.

In addition to the keys reported in the above table, a similar content is created per CPU core. The cores are listed from 0 to N as the Kernel reports:

Configuration Parameters

The plugin supports the following configuration parameters:

Getting Started

In order to get the statistics of the CPU usage of your system, you can run the plugin from the command line or through the configuration file:

Command Line

$ build/bin/fluent-bit -i cpu -t my_cpu -o stdout -m '*'
Fluent Bit v1.x.x
* Copyright (C) 2019-2020 The Fluent Bit Authors
* Copyright (C) 2015-2018 Treasure Data
* Fluent Bit is a CNCF sub-project under the umbrella of Fluentd
* https://fluentbit.io

[2019/09/02 10:46:29] [ info] starting engine
[0] [1452185189, {"cpu_p"=>7.00, "user_p"=>5.00, "system_p"=>2.00, "cpu0.p_cpu"=>10.00, "cpu0.p_user"=>8.00, "cpu0.p_system"=>2.00, "cpu1.p_cpu"=>6.00, "cpu1.p_user"=>4.00, "cpu1.p_system"=>2.00}]
[1] [1452185190, {"cpu_p"=>6.50, "user_p"=>5.00, "system_p"=>1.50, "cpu0.p_cpu"=>6.00, "cpu0.p_user"=>5.00, "cpu0.p_system"=>1.00, "cpu1.p_cpu"=>7.00, "cpu1.p_user"=>5.00, "cpu1.p_system"=>2.00}]
[2] [1452185191, {"cpu_p"=>7.50, "user_p"=>5.00, "system_p"=>2.50, "cpu0.p_cpu"=>7.00, "cpu0.p_user"=>3.00, "cpu0.p_system"=>4.00, "cpu1.p_cpu"=>6.00, "cpu1.p_user"=>6.00, "cpu1.p_system"=>0.00}]
[3] [1452185192, {"cpu_p"=>4.50, "user_p"=>3.50, "system_p"=>1.00, "cpu0.p_cpu"=>6.00, "cpu0.p_user"=>5.00, "cpu0.p_system"=>1.00, "cpu1.p_cpu"=>5.00, "cpu1.p_user"=>3.00, "cpu1.p_system"=>2.00}]

As described above, the CPU input plugin gathers the overall usage every one second and flushed the information to the output on the fifth second. On this example we used the stdout plugin to demonstrate the output records. In a real use-case you may want to flush this information to some central aggregator such as Fluentd or Elasticsearch.

Configuration File

In your main configuration file append the following Input & Output sections:

[INPUT]
    Name cpu
    Tag  my_cpu

[OUTPUT]
    Name  stdout
    Match *

pipeline:
    inputs:
        - name: cpu
          tag: my_cpu

    outputs:
        - name: stdout
          match: '*'

The dummy input plugin, generates dummy events. It is useful for testing, debugging, benchmarking and getting started with Fluent Bit.

Configuration Parameters

The plugin supports the following configuration parameters:

Getting Started

You can run the plugin from the command line or through the configuration file:

Command Line

$ fluent-bit -i dummy -o stdout
Fluent Bit v2.x.x
* Copyright (C) 2015-2022 The Fluent Bit Authors
* Fluent Bit is a CNCF sub-project under the umbrella of Fluentd
* https://fluentbit.io

[0] dummy.0: [[1686451466.659962491, {}], {"message"=>"dummy"}]
[0] dummy.0: [[1686451467.659679509, {}], {"message"=>"dummy"}]

Configuration File

In your main configuration file append the following Input & Output sections:

[INPUT]
    Name   dummy
    Dummy {"message": "custom dummy"}

[OUTPUT]
    Name   stdout
    Match  *

pipeline:
  inputs:
    - name: dummy
      dummy: '{"message": "custom dummy"}'
  outputs:
    - name: stdout
      match: '*'

The disk input plugin, gathers the information about the disk throughput of the running system every certain interval of time and reports them.

The Disk 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.

Configuration Parameters

The plugin supports the following configuration parameters:

Getting Started

In order to get disk usage from your system, you can run the plugin from the command line or through the configuration file:

Command Line

$ fluent-bit -i disk -o stdout
Fluent Bit v1.x.x
* Copyright (C) 2019-2020 The Fluent Bit Authors
* Copyright (C) 2015-2018 Treasure Data
* Fluent Bit is a CNCF sub-project under the umbrella of Fluentd
* https://fluentbit.io

[2017/01/28 16:58:16] [ info] [engine] started
[0] disk.0: [1485590297, {"read_size"=>0, "write_size"=>0}]
[1] disk.0: [1485590298, {"read_size"=>0, "write_size"=>0}]
[2] disk.0: [1485590299, {"read_size"=>0, "write_size"=>0}]
[3] disk.0: [1485590300, {"read_size"=>0, "write_size"=>11997184}]

Configuration File

In your main configuration file append the following Input & Output sections:

[INPUT]
    Name          disk
    Tag           disk
    Interval_Sec  1
    Interval_NSec 0
[OUTPUT]
    Name   stdout
    Match  *

pipeline:
    inputs:
        - name: disk
          tag: disk
          interval_sec: 1
          interval_nsec: 0
    outputs:
        - name: stdout
          match: '*'

Note: Total interval (sec) = Interval_Sec + (Interval_Nsec / 1000000000).

e.g. 1.5s = 1s + 500000000ns

The exec_wasi input plugin, allows to execute WASM program that is WASI target like as external program and collects event logs from there.

Configuration Parameters

The plugin supports the following configuration parameters:

Configuration Examples

Here is a configuration example. in_exec_wasi can handle parser. To retrieve from structured data from WASM program, you have to create parser.conf:

Note that Time_Format should be aligned for the format of your using timestamp. In this documents, we assume that WASM program should write JSON style strings into stdout.

[PARSER]
    Name        wasi
    Format      json
    Time_Key    time
    Time_Format %Y-%m-%dT%H:%M:%S.%L %z

Then, you can specify the above parsers.conf in the main fluent-bit configuration:

[SERVICE]
    Flush        1
    Daemon       Off
    Parsers_File parsers.conf
    Log_Level    info
    HTTP_Server  Off
    HTTP_Listen  0.0.0.0
    HTTP_Port    2020

[INPUT]
    Name exec_wasi
    Tag  exec.wasi.local
    WASI_Path /path/to/wasi/program.wasm
    Accessible_Paths .,/path/to/accessible
    Parser wasi

[OUTPUT]
    Name  stdout
    Match *