Health

Health input plugin allows you to check how healthy a TCP server is. It does the check by issuing a TCP connection every a certain interval of time.

Configuration Parameters

The plugin supports the following configuration parameters:

Key	Description
Host	Name of the target host or IP address to check.
Port	TCP port where to perform the connection check.
Interval_Sec	Interval in seconds between the service checks. Default value is 1.
Internal_Nsec	Specify a nanoseconds interval for service checks, it works in conjunction with the Interval_Sec configuration key. Default value is 0.
Alert	If enabled, it will only generate messages if the target TCP service is down. By default this option is disabled.
Add_Host	If enabled, hostname is appended to each records. Default value is false.
Add_Port	If enabled, port number is appended to each records. Default value is false.
Threaded	Indicates whether to run this input in its own thread. Default: false.

Getting Started

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

Command Line

From the command line you can let Fluent Bit generate the checks with the following options:

$ fluent-bit -i health -p host=127.0.0.1 -p port=80 -o stdout

Configuration File

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

fluent-bit.conf

[INPUT]
    Name          health
    Host          127.0.0.1
    Port          80
    Interval_Sec  1
    Interval_NSec 0

[OUTPUT]
    Name   stdout
    Match  *

fluent-bit.yaml

Testing

Once Fluent Bit is running, you will see some random values in the output interface similar to this:

$ fluent-bit -i health -p host=127.0.0.1 -p port=80 -o stdout
Fluent Bit v1.8.0
* Copyright (C) 2019-2021 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

[2021/06/20 08:39:47] [ info] [engine] started (pid=4621)
[2021/06/20 08:39:47] [ info] [storage] version=1.1.1, initializing...
[2021/06/20 08:39:47] [ info] [storage] in-memory
[2021/06/20 08:39:47] [ info] [storage] normal synchronization mode, checksum disabled, max_chunks_up=128
[2021/06/20 08:39:47] [ info] [sp] stream processor started
[0] health.0: [1624145988.305640385, {"alive"=>true}]
[1] health.0: [1624145989.305575360, {"alive"=>true}]
[2] health.0: [1624145990.306498573, {"alive"=>true}]
[3] health.0: [1624145991.305595498, {"alive"=>true}]