---
title: "discovery.nerve | Grafana Alloy documentation"
description: "Learn about discovery.nerve"
---

# `discovery.nerve`

`discovery.nerve` discovers [airbnb/nerve](https://github.com/airbnb/nerve) targets stored in Zookeeper.

## Usage

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

```alloy
discovery.nerve "<LABEL>" {
    servers = ["<SERVER_1>", "<SERVER_2>"]
    paths   = ["<PATH_1>", "<PATH_2>"]
}
```

## Arguments

You can use the following arguments with `discovery.nerve`:

Expand table

| Name      | Type           | Description                       | Default | Required |
|-----------|----------------|-----------------------------------|---------|----------|
| `paths`   | `list(string)` | The paths to look for targets at. |         | yes      |
| `servers` | `list(string)` | The Zookeeper servers.            |         | yes      |
| `timeout` | `duration`     | The timeout to use.               | `"10s"` | no       |

Each element in the `path` list can either point to a single service, or to the root of a tree of services.

## Blocks

The `discovery.nerve` component doesn’t support any blocks. You can configure this component with arguments.

## Exported fields

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

Expand table

| Name      | Type                | Description                                     |
|-----------|---------------------|-------------------------------------------------|
| `targets` | `list(map(string))` | The set of targets discovered from Nerve’s API. |

The following meta labels are available on targets and can be used by the discovery.relabel component

- `__meta_nerve_endpoint_host`: The host of the endpoint.
- `__meta_nerve_endpoint_name`: The name of the endpoint.
- `__meta_nerve_endpoint_port`: The port of the endpoint.
- `__meta_nerve_path`: The full path to the endpoint node in Zookeeper.

## Component health

`discovery.nerve` is only reported as unhealthy when given an invalid configuration. In those cases, exported fields retain their last healthy values.

## Debug information

`discovery.nerve` doesn’t expose any component-specific debug information.

## Debug metrics

`discovery.nerve` doesn’t expose any component-specific debug metrics.

## Example

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

```alloy
discovery.nerve "example" {
    servers = ["localhost"]
    paths   = ["/monitoring"]
    timeout = "1m"
}
prometheus.scrape "demo" {
    targets    = discovery.nerve.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

`discovery.nerve` 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.