Standard Output

The standard output filter allows printing the data flowing through the filter plugin to stdout, which can be used while debugging.

The plugin has no configuration parameters.

Command line

Use the following command from the command line:

$ ./fluent-bit -i cpu -F stdout -m '*' -o null

Fluent Bit specifies gathering CPU usage metrics and prints them out in a human-readable way when they flow through the stdout plugin.

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 /\___  |\ |_/ /
\_|   |_|\__,_|\___|_| |_|\__| \____/|_|\__|   \_/     |_(_)___/


[2025/07/03 16:15:34] [ info] [fluent bit] version=4.0.3, commit=3a91b155d6, pid=23196
[2025/07/03 16:15:34] [ info] [storage] ver=1.5.3, type=memory, sync=normal, checksum=off, max_chunks_up=128
[2025/07/03 16:15:34] [ info] [simd    ] disabled
[2025/07/03 16:15:34] [ info] [cmetrics] version=1.0.3
[2025/07/03 16:15:34] [ info] [ctraces ] version=0.6.6
[2025/07/03 16:15:34] [ info] [input:dummy:dummy.0] initializing
[2025/07/03 16:15:34] [ info] [input:dummy:dummy.0] storage_strategy='memory' (memory only)
[2025/07/03 16:15:34] [ info] [output:stdout:stdout.0] worker #0 started
[2025/07/03 16:15:34] [ info] [sp] stream processor started
[0] cpu.0: [1622789640.379532062, {"cpu_p"=>9.000000, "user_p"=>6.500000, "system_p"=>2.500000, "cpu0.p_cpu"=>8.000000, "cpu0.p_user"=>6.000000, "cpu0.p_system"=>2.000000, "cpu1.p_cpu"=>9.000000, "cpu1.p_user"=>6.000000, "cpu1.p_system"=>3.000000}]
[0] cpu.0: [1622789641.379529426, {"cpu_p"=>22.500000, "user_p"=>18.000000, "system_p"=>4.500000, "cpu0.p_cpu"=>34.000000, "cpu0.p_user"=>30.000000, "cpu0.p_system"=>4.000000, "cpu1.p_cpu"=>11.000000, "cpu1.p_user"=>6.000000, "cpu1.p_system"=>5.000000}]
[0] cpu.0: [1622789642.379544020, {"cpu_p"=>26.500000, "user_p"=>16.000000, "system_p"=>10.500000, "cpu0.p_cpu"=>30.000000, "cpu0.p_user"=>24.000000, "cpu0.p_system"=>6.000000, "cpu1.p_cpu"=>22.000000, "cpu1.p_user"=>8.000000, "cpu1.p_system"=>14.000000}]
[0] cpu.0: [1622789643.379507371, {"cpu_p"=>39.500000, "user_p"=>34.500000, "system_p"=>5.000000, "cpu0.p_cpu"=>52.000000, "cpu0.p_user"=>48.000000, "cpu0.p_system"=>4.000000, "cpu1.p_cpu"=>28.000000, "cpu1.p_user"=>21.000000, "cpu1.p_system"=>7.000000}]
^C[2021/06/04 14:54:04] [engine] caught signal (SIGINT)
[2021/06/04 14:54:04] [ info] [input] pausing cpu.0
[2021/06/04 14:54:04] [ warn] [engine] service will stop in 5 seconds
[2021/06/04 14:54:08] [ info] [engine] service stopped