---
title: "prometheus.exporter.postgres | Grafana Agent documentation"
description: "Learn about prometheus.exporter.postgres"
---

# prometheus.exporter.postgres

The `prometheus.exporter.postgres` component embeds [postgres\_exporter](https://github.com/prometheus-community/postgres_exporter) for collecting metrics from a postgres database.

Multiple `prometheus.exporter.postgres` components can be specified by giving them different labels.

## Usage

Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```alloy
prometheus.exporter.postgres "LABEL" {
    data_source_names = DATA_SOURCE_NAMES_LIST
}
```

## Arguments

The following arguments are supported:

Expand table

| Name                         | Type           | Description                                                                   | Default | Required |
|------------------------------|----------------|-------------------------------------------------------------------------------|---------|----------|
| `data_source_names`          | `list(secret)` | Specifies the Postgres server(s) to connect to.                               |         | yes      |
| `disable_settings_metrics`   | `bool`         | Disables collection of metrics from pg\_settings.                             | `false` | no       |
| `disable_default_metrics`    | `bool`         | When `true`, only exposes metrics supplied from `custom_queries_config_path`. | `false` | no       |
| `custom_queries_config_path` | `string`       | Path to YAML file containing custom queries to expose as metrics.             | ""      | no       |
| `enabled_collectors`         | `list(string)` | List of collectors to enable. See below for more detail.                      | \[]     | no       |

The format for connection strings in `data_source_names` can be found in the [official postgresql documentation](https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING).

See examples for the `custom_queries_config_path` file in the [postgres\_exporter repository](https://github.com/prometheus-community/postgres_exporter/blob/master/queries.yaml).

**NOTE**: There are a number of environment variables that are not recommended for use, as they will affect *all* `prometheus.exporter.postgres` components. A full list can be found in the [postgres\_exporter repository](https://github.com/prometheus-community/postgres_exporter#environment-variables).

By default, the same set of metrics is enabled as in the upstream [postgres\_exporter](https://github.com/prometheus-community/postgres_exporter/). If `custom_queries_config_path` is set, additional metrics defined in the given config file will be exposed. If `disable_default_metrics` is set to `true`, only the metrics defined in the `custom_queries_config_path` file will be exposed.

A subset of metrics collectors can be controlled by setting the `enabled_collectors` argument. The following collectors are available for selection: `database`, `database_wraparound`, `locks`, `long_running_transactions`, `postmaster`, `process_idle`, `replication`, `replication_slot`, `stat_activity_autovacuum`, `stat_bgwriter`, `stat_database`, `stat_statements`, `stat_user_tables`, `stat_wal_receiver`, `statio_user_indexes`, `statio_user_tables`, `wal`, `xlog_location`.

By default, the following collectors are enabled: `database`, `locks`, `replication`, `replication_slot`, `stat_bgwriter`, `stat_database`, `stat_user_tables`, `statio_user_tables`, `wal`.

> Note
> 
> Due to a limitation of the upstream exporter, when multiple `data_source_names` are used, the collectors that are controlled via the `enabled_collectors` argument will only be applied to the first data source in the list.

## Blocks

The following blocks are supported:

Expand table

| Hierarchy     | Block                                 | Description                  | Required |
|---------------|---------------------------------------|------------------------------|----------|
| autodiscovery | [autodiscovery](#autodiscovery-block) | Database discovery settings. | no       |

### autodiscovery block

The `autodiscovery` block configures discovery of databases, outside of any specified in `data_source_names`.

The following arguments are supported:

Expand table

| Name                 | Type           | Description                                                                    | Default | Required |
|----------------------|----------------|--------------------------------------------------------------------------------|---------|----------|
| `enabled`            | `bool`         | Whether to autodiscover other databases                                        | `false` | no       |
| `database_allowlist` | `list(string)` | List of databases to filter for, meaning only these databases will be scraped. |         | no       |
| `database_denylist`  | `list(string)` | List of databases to filter out, meaning all other databases will be scraped.  |         | no       |

If `enabled` is set to `true` and no allowlist or denylist is specified, the exporter will scrape from all databases.

If `autodiscovery` is disabled, neither `database_allowlist` nor `database_denylist` will have any effect.

## Exported fields

The following fields are exported and can be referenced by other components.

Expand table

| Name      | Type                | Description                                               |
|-----------|---------------------|-----------------------------------------------------------|
| `targets` | `list(map(string))` | The targets that can be used to collect exporter metrics. |

For example, the `targets` can either be passed to a `discovery.relabel` component to rewrite the targets’ label sets or to a `prometheus.scrape` component that collects the exposed metrics.

The exported targets use the configured [in-memory traffic](/docs/agent/v0.43/flow/concepts/component_controller/#in-memory-traffic) address specified by the [run command](/docs/agent/v0.43/flow/reference/cli/run/).

## Component health

`prometheus.exporter.postgres` is only reported as unhealthy if given an invalid configuration.

## Debug information

`prometheus.exporter.postgres` does not expose any component-specific debug information.

## Debug metrics

`prometheus.exporter.postgres` does not expose any component-specific debug metrics.

## Examples

### Collect metrics from a PostgreSQL server

This example uses a `prometheus.exporter.postgres` component to collect metrics from a Postgres server running locally with all default settings:

Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```alloy
// Because no autodiscovery is defined, this will only scrape the 'database_name' database, as defined
// in the DSN below.
prometheus.exporter.postgres "example" {
  data_source_names = ["postgresql://username:password@localhost:5432/database_name?sslmode=disable"]
}

prometheus.scrape "default" {
  targets    = prometheus.exporter.postgres.example.targets
  forward_to = [prometheus.remote_write.demo.receiver]
}

prometheus.remote_write "demo" {
  endpoint {
    url = PROMETHEUS_REMOTE_WRITE_URL

    basic_auth {
      username = USERNAME
      password = PASSWORD
    }
  }
}
```

Replace the following:

- `PROMETHEUS_REMOTE_WRITE_URL`: The URL of the Prometheus remote\_write-compatible server to send metrics to.
- `USERNAME`: The username to use for authentication to the remote\_write API.
- `PASSWORD`: The password to use for authentication to the remote\_write API.

### Collect custom metrics from an allowlisted set of databases

This example uses a `prometheus.exporter.postgres` component to collect custom metrics from a set of specific databases, replacing default metrics with custom metrics derived from queries in `/etc/agent/custom-postgres-metrics.yaml`:

Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```alloy
prometheus.exporter.postgres "example" {
  data_source_names = ["postgresql://username:password@localhost:5432/database_name?sslmode=disable"]

  // This block configures autodiscovery to check for databases outside of the 'database_name' db
  // specified in the DSN above. The database_allowlist field means that only the 'frontend_app' and 'backend_app'
  // databases will be scraped.
  autodiscovery {
    enabled            = true
    database_allowlist = ["frontend_app", "backend_app"]
  }

  disable_default_metrics    = true
  custom_queries_config_path = "/etc/agent/custom-postgres-metrics.yaml"
}

prometheus.scrape "default" {
  targets    = prometheus.exporter.postgres.example.targets
  forward_to = [prometheus.remote_write.demo.receiver]
}

prometheus.remote_write "demo" {
  endpoint {
    url = PROMETHEUS_REMOTE_WRITE_URL

    basic_auth {
      username = USERNAME
      password = PASSWORD
    }
  }
}
```

Replace the following:

- `PROMETHEUS_REMOTE_WRITE_URL`: The URL of the Prometheus remote\_write-compatible server to send metrics to.
- `USERNAME`: The username to use for authentication to the remote\_write API.
- `PASSWORD`: The password to use for authentication to the remote\_write API.

### Collect metrics from all databases except for a denylisted database

This example uses a `prometheus.exporter.postgres` component to collect custom metrics from all databases except for the `secrets` database.

Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```alloy
prometheus.exporter.postgres "example" {
  data_source_names = ["postgresql://username:password@localhost:5432/database_name?sslmode=disable"]

  // The database_denylist field will filter out those databases from the list of databases to scrape,
  // meaning that all databases *except* these will be scraped.
  //
  // In this example it will scrape all databases except for the one named 'secrets'.
  autodiscovery {
    enabled           = true
    database_denylist = ["secrets"]
  }
}

prometheus.scrape "default" {
  targets    = prometheus.exporter.postgres.example.targets
  forward_to = [prometheus.remote_write.demo.receiver]
}

prometheus.remote_write "demo" {
  endpoint {
    url = PROMETHEUS_REMOTE_WRITE_URL

    basic_auth {
      username = USERNAME
      password = PASSWORD
    }
  }
}
```

Replace the following:

- `PROMETHEUS_REMOTE_WRITE_URL`: The URL of the Prometheus remote\_write-compatible server to send metrics to.
- `USERNAME`: The username to use for authentication to the remote\_write API.
- `PASSWORD`: The password to use for authentication to the remote\_write API.

## Compatible components

`prometheus.exporter.postgres` has exports that can be consumed by the following components:

- Components that consume [Targets](../../compatibility/#targets-consumers)

> Note
> 
> Connecting some components may not be sensible or components may require further configuration to make the connection work correctly. Refer to the linked documentation for more details.