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.

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:

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

[OUTPUT]
    Name   stdout
    Match  *

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}]