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 | | :--- | :--- | | Host | Name of the target host or IP address. | none | | Port | TCP port where to perform the connection request. | none | | Interval_Sec | Interval in seconds between the service checks.| 1 | | Internal_Nsec | Specify a nanoseconds interval for service checks. Works in conjunction with the Interval_Sec configuration key. | 0 | | Alert | If enabled, it generates messages if the target TCP service is down. | false | | Add_Host | If enabled, hostname is appended to each records. | false | | Add_Port | If enabled, port number is appended to each records. | false | | 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 Input and 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

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