Process Log Based Metrics

The Process metrics input plugin lets you check how healthy a process is. It does so by performing service checks at specified intervals.

This plugin creates metrics that are log-based, such as JSON payloads. For Prometheus-based metrics, see the Node exporter metrics input plugin.

Configuration parameters

The plugin supports the following configuration parameters:

Key
Description
Default

Proc_Name

The name of the target process to check.

none

Interval_Sec

Specifies the interval between service checks, in seconds.

1

Interval_Nsec

Specifies the interval between service checks, in nanoseconds. This works in conjunction with Interval_Sec.

0

Alert

If enabled, the plugin will only generate messages if the target process is down.

false

Fd

If enabled, a number of fd is appended to each record.

true

Mem

If enabled, memory usage of the process is appended to each record.

true

Threaded

Specifies whether to run this input in its own thread.

false

Get started

To start performing the checks, you can run the plugin from the command line or through the configuration file:

The following example checks the health of crond process.

$ fluent-bit -i proc -p proc_name=crond -o stdout

Configuration file

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

pipeline:
    inputs:
        - name: proc
          proc_name: crond
          interval_sec: 1
          interval_nsec: 0
          fd: true
          mem: true

    outputs:
        - name: stdout
          match: '*'

Testing

After Fluent Bit starts running, it outputs the health of the process:

$ fluent-bit -i proc -p proc_name=fluent-bit -o stdout

Fluent Bit v4.0.3
* Copyright (C) 2015-2025 The Fluent Bit Authors
* Fluent Bit is a CNCF sub-project under the umbrella of Fluentd
* https://fluentbit.io

______ _                  _    ______ _ _             ___  _____
|  ___| |                | |   | ___ (_) |           /   ||  _  |
| |_  | |_   _  ___ _ __ | |_  | |_/ /_| |_  __   __/ /| || |/' |
|  _| | | | | |/ _ \ '_ \| __| | ___ \ | __| \ \ / / /_| ||  /| |
| |   | | |_| |  __/ | | | |_  | |_/ / | |_   \ V /\___  |\ |_/ /
\_|   |_|\__,_|\___|_| |_|\__| \____/|_|\__|   \_/     |_(_)___/


[2025/07/01 14:44:47] [ info] [fluent bit] version=4.0.3, commit=f5f5f3c17d, pid=1
[2025/07/01 14:44:47] [ info] [storage] ver=1.5.3, type=memory, sync=normal, checksum=off, max_chunks_up=128
[2025/07/01 14:44:47] [ info] [simd    ] disabled
[2025/07/01 14:44:47] [ info] [cmetrics] version=1.0.3
[2025/07/01 14:44:47] [ info] [ctraces ] version=0.6.6
[2025/07/01 14:44:47] [ info] [input:mem:mem.0] initializing
[2025/07/01 14:44:47] [ info] [input:mem:mem.0] storage_strategy='memory' (memory only)
[2025/07/01 14:44:47] [ info] [sp] stream processor started
[2025/07/01 14:44:47] [ info] [engine] Shutdown Grace Period=5, Shutdown Input Grace Period=2
[2025/07/01 14:44:47] [ info] [output:stdout:stdout.0] worker #0 started
[0] proc.0: [1485780297, {"alive"=>true, "proc_name"=>"fluent-bit", "pid"=>10964, "mem.VmPeak"=>14740000, "mem.VmSize"=>14740000, "mem.VmLck"=>0, "mem.VmHWM"=>1120000, "mem.VmRSS"=>1120000, "mem.VmData"=>2276000, "mem.VmStk"=>88000, "mem.VmExe"=>1768000, "mem.VmLib"=>2328000, "mem.VmPTE"=>68000, "mem.VmSwap"=>0, "fd"=>18}]
[1] proc.0: [1485780298, {"alive"=>true, "proc_name"=>"fluent-bit", "pid"=>10964, "mem.VmPeak"=>14740000, "mem.VmSize"=>14740000, "mem.VmLck"=>0, "mem.VmHWM"=>1148000, "mem.VmRSS"=>1148000, "mem.VmData"=>2276000, "mem.VmStk"=>88000, "mem.VmExe"=>1768000, "mem.VmLib"=>2328000, "mem.VmPTE"=>68000, "mem.VmSwap"=>0, "fd"=>18}]
[2] proc.0: [1485780299, {"alive"=>true, "proc_name"=>"fluent-bit", "pid"=>10964, "mem.VmPeak"=>14740000, "mem.VmSize"=>14740000, "mem.VmLck"=>0, "mem.VmHWM"=>1152000, "mem.VmRSS"=>1148000, "mem.VmData"=>2276000, "mem.VmStk"=>88000, "mem.VmExe"=>1768000, "mem.VmLib"=>2328000, "mem.VmPTE"=>68000, "mem.VmSwap"=>0, "fd"=>18}]
[3] proc.0: [1485780300, {"alive"=>true, "proc_name"=>"fluent-bit", "pid"=>10964, "mem.VmPeak"=>14740000, "mem.VmSize"=>14740000, "mem.VmLck"=>0, "mem.VmHWM"=>1152000, "mem.VmRSS"=>1148000, "mem.VmData"=>2276000, "mem.VmStk"=>88000, "mem.VmExe"=>1768000, "mem.VmLib"=>2328000, "mem.VmPTE"=>68000, "mem.VmSwap"=>0, "fd"=>18}]

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