# 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](https://docs.fluentbit.io/manual/3.1/administration/multithreading#inputs). 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:

```bash
$ 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:

{% tabs %}
{% tab title="fluent-bit.conf" %}

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

[OUTPUT]
    Name   stdout
    Match  *
```

{% endtab %}

{% tab title="fluent-bit.yaml" %}

```yaml
pipeline:
    inputs:
        - name: health
          host: 127.0.0.1
          port: 80
          interval_sec: 1
          interval_nsec: 0
    outputs:
        - name: stdout
          match: '*'
```

{% endtab %}
{% endtabs %}

## Testing

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

```bash
$ 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}]
```