# Prometheus remote write

{% hint style="info" %}
**Supported event types:** `metrics`
{% endhint %}

The *Prometheus remote write* input plugin lets you ingest a payload in the Prometheus remote-write format. A remote-write sender can transmit data to Fluent Bit.

## Configuration parameters

The table below includes both:

* settings specific to the Prometheus remote write input plugin
* shared `http_server.*` listener settings that are used by several HTTP-based inputs

For a cross-plugin explanation of the shared listener settings, see [Shared HTTP listener settings for inputs](https://docs.fluentbit.io/manual/administration/configuring-fluent-bit/yaml/pipeline-section#shared-http-listener-settings-for-inputs).

| Key                                     | Description                                                                                                                                                                                                                                      | Default   |
| --------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | --------- |
| `buffer_chunk_size`                     | Sets the chunk size for incoming data. These chunks are then stored and managed in the space specified by `buffer_max_size`. Compatibility alias for `http_server.buffer_chunk_size`.                                                            | `512K`    |
| `buffer_max_size`                       | Specifies the maximum buffer size to receive a request. Compatibility alias for `http_server.buffer_max_size`.                                                                                                                                   | `4M`      |
| `http2`                                 | Enable HTTP/2 support. Compatibility alias for `http_server.http2`.                                                                                                                                                                              | `true`    |
| `http_server.max_connections`           | Maximum number of concurrent active HTTP connections. `0` means unlimited.                                                                                                                                                                       | `0`       |
| `http_server.workers`                   | Number of HTTP listener worker threads.                                                                                                                                                                                                          | `1`       |
| `http_server.ingress_queue_event_limit` | Maximum number of deferred ingress queue entries. Applies only when `http_server.workers` is greater than `1`.                                                                                                                                   | `8192`    |
| `http_server.ingress_queue_byte_limit`  | Maximum size of the deferred ingress queue. Applies only when `http_server.workers` is greater than `1`.                                                                                                                                         | `256M`    |
| `listen`                                | The address to listen on.                                                                                                                                                                                                                        | `0.0.0.0` |
| `port`                                  | The port to listen on.                                                                                                                                                                                                                           | `8080`    |
| `successful_response_code`              | Specifies the success response code. Supported values are `200`, `201`, and `204`.                                                                                                                                                               | `201`     |
| `tag_from_uri`                          | If true, a tag will be created from the `uri` parameter (for example, `api_prom_push` from `/api/prom/push`), and any tag specified in the configuration will be ignored. If false, you must provide a tag in the configuration for this plugin. | `true`    |
| `threaded`                              | Specifies whether to run this input in its own [thread](https://docs.fluentbit.io/manual/administration/multithreading#inputs).                                                                                                                  | `false`   |
| `uri`                                   | Specifies an optional HTTP URI for the target web server listening for Prometheus remote write payloads (for example, `/api/prom/push`).                                                                                                         | *none*    |

The `http_server.ingress_queue_event_limit` and `http_server.ingress_queue_byte_limit` settings matter only when `http_server.workers` is greater than `1`.

## Configuration file

The following examples are sample configuration files for this input plugin:

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

```yaml
pipeline:
  inputs:
    - name: prometheus_remote_write
      listen: 127.0.0.1
      port: 8080
      uri: /api/prom/push

  outputs:
    - name: stdout
      match: '*'
```

{% endtab %}

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

```
[INPUT]
  name prometheus_remote_write
  listen 127.0.0.1
  port 8080
  uri /api/prom/push

[OUTPUT]
  name stdout
  match *
```

{% endtab %}
{% endtabs %}

These sample configurations configure Fluent Bit to listen for data on port `8080`. You can send payloads in Prometheus remote-write format to the endpoint `/api/prom/push`.

## Examples

### Communicate with TLS

The Prometheus remote write input plugin supports TLS and SSL. For more details about the properties available and general configuration, refer to the [Transport security](https://docs.fluentbit.io/manual/administration/transport-security) documentation.

To communicate with TLS, you must use these TLS-related parameters:

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

```yaml
pipeline:
  inputs:
    - name: prometheus_remote_write
      listen: 127.0.0.1
      port: 8080
      uri: /api/prom/push
      tls: on
      tls.crt_file: /path/to/certificate.crt
      tls.key_file: /path/to/certificate.key
```

{% endtab %}

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

```
[INPUT]
  Name prometheus_remote_write
  Listen 127.0.0.1
  Port 8080
  Uri /api/prom/push
  Tls On
  tls.crt_file /path/to/certificate.crt
  tls.key_file /path/to/certificate.key
```

{% endtab %}
{% endtabs %}

Now, you should be able to send data over TLS to the remote-write input.