---
layout: docs
page_title: Nomad Node Pool Specification
description: Learn about Nomad's Node Pool specification.
---

# Nomad Node Pool Specification

Nomad node pools may be specified as HCL files and submitted by the [`nomad node
pool apply`][pool-apply] CLI command.

Unlike [Job specifications][jobspecs], Nomad node pool specifications do *not*
support HCL2 features like functions.

Example node pool specification generated by [`nomad node pool
init`][pool-init]:

```hcl
node_pool "example" {

  description = "Example node pool"

  # meta is optional metadata on the node pool, defined as key-value pairs.
  # The scheduler does not use node pool metadata as part of scheduling.
  meta {
    environment = "prod"
    owner       = "sre"
  }

  # The scheduler configuration options specific to this node pool. This block
  # supports a subset of the fields supported in the global scheduler
  # configuration as described at:
  # https://developer.hashicorp.com/nomad/docs/commands/operator/scheduler/set-config
  #
  # * scheduler_algorithm is the scheduling algorithm to use for the pool.
  #   If not defined, the global cluster scheduling algorithm is used.
  #
  # Available only in Nomad Enterprise.

  # scheduler_config {
  #   scheduler_algorithm = "spread"
  # }
}
```

Example usage if the above is in a file named `pool.nomad.hcl`:

```shell-session
$ nomad node pool apply ./pool.nomad.hcl
Successfully applied node pool "example"!
```

## Node Pool Specification Parameters

- `description` `(string: <optional>)` - Sets a human readable description for
  the node pool.

- `meta` `(map[string]string: <optional>)` - Sets optional metadata on the node
  pool, defined as key-value pairs. The scheduler does not use node pool
  metadata as part of scheduling.

- `scheduler_config` <code>([SchedulerConfig][sched-config]: nil)</code> <EnterpriseAlert inline /> -
  Sets scheduler configuration options specific to the node pool. If not
  defined, the global scheduler configurations are used.

### `scheduler_config` Parameters <EnterpriseAlert inline />

- `scheduler_algorithm` `(string: <optional>)` - The [scheduler algorithm][]
  used for this node pool. Must be one of `binpack` or `spread`.

- `memory_oversubscription_enabled` `(bool: <optional>)` - The [memory
  oversubscription][] setting to use for this node pool.

[pool-apply]: /nomad/docs/commands/node-pool/apply
[jobspecs]: /nomad/docs/job-specification
[pool-init]: /nomad/docs/commands/node-pool/init
[sched-config]: #scheduler_config-parameters
[scheduler algorithm]: /nomad/api-docs/operator/scheduler#scheduleralgorithm-1
[memory oversubscription]: /nomad/api-docs/operator/scheduler#memoryoversubscriptionenabled-1
