Health

The Health input plugin lets you check how healthy a TCP server is. It checks by issuing a TCP connection at regular intervals.

Configuration parameters

The plugin supports the following configuration parameters:

Key	Description	Default
add_host	If enabled, hostname is appended to each record.	false
add_port	If enabled, port number is appended to each record.	false
alert	If enabled, it generates messages only when the target TCP service is down.	false
host	Name of the target host or IP address.	none
interval_nsec	Specify a nanoseconds interval for service checks. Works with the interval_sec configuration key.	0
interval_sec	Interval in seconds between the service checks.	1
port	TCP port where to perform the connection request.	none
threaded	Indicates 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:

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:

fluent-bit.yaml

pipeline:
  inputs:
    - name: health
      host: 127.0.0.1
      port: 80
      interval_sec: 1
      interval_nsec: 0

  outputs:
    - name: stdout
      match: '*'

fluent-bit.conf

Testing

Once Fluent Bit is running, you will see health check results in the output interface similar to this:

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

...
[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}]
...