# Class: Pool
Extends: `undici.Dispatcher`
A pool of [Client](Client.md) instances connected to the same upstream target.
Requests are not guaranteed to be dispatched in order of invocation.
## `new Pool(url[, options])`
Arguments:
* **url** `URL | string` - It should only include the **protocol, hostname, and port**.
* **options** `PoolOptions` (optional)
### Parameter: `PoolOptions`
Extends: [`ClientOptions`](Client.md#parameter-clientoptions)
* **factory** `(origin: URL, opts: Object) => Dispatcher` - Default: `(origin, opts) => new Client(origin, opts)`
* **connections** `number | null` (optional) - Default: `null` - The number of `Client` instances to create. When set to `null`, the `Pool` instance will create an unlimited amount of `Client` instances.
* **interceptors** `{ Pool: DispatchInterceptor[] } }` - Default: `{ Pool: [] }` - A list of interceptors that are applied to the dispatch method. Additional logic can be applied (such as, but not limited to: 302 status code handling, authentication, cookies, compression and caching).
## Instance Properties
### `Pool.closed`
Implements [Client.closed](Client.md#clientclosed)
### `Pool.destroyed`
Implements [Client.destroyed](Client.md#clientdestroyed)
### `Pool.stats`
Returns [`PoolStats`](PoolStats.md) instance for this pool.
## Instance Methods
### `Pool.close([callback])`
Implements [`Dispatcher.close([callback])`](Dispatcher.md#dispatcherclosecallback-promise).
### `Pool.destroy([error, callback])`
Implements [`Dispatcher.destroy([error, callback])`](Dispatcher.md#dispatcherdestroyerror-callback-promise).
### `Pool.connect(options[, callback])`
See [`Dispatcher.connect(options[, callback])`](Dispatcher.md#dispatcherconnectoptions-callback).
### `Pool.dispatch(options, handler)`
Implements [`Dispatcher.dispatch(options, handler)`](Dispatcher.md#dispatcherdispatchoptions-handler).
### `Pool.pipeline(options, handler)`
See [`Dispatcher.pipeline(options, handler)`](Dispatcher.md#dispatcherpipelineoptions-handler).
### `Pool.request(options[, callback])`
See [`Dispatcher.request(options [, callback])`](Dispatcher.md#dispatcherrequestoptions-callback).
### `Pool.stream(options, factory[, callback])`
See [`Dispatcher.stream(options, factory[, callback])`](Dispatcher.md#dispatcherstreamoptions-factory-callback).
### `Pool.upgrade(options[, callback])`
See [`Dispatcher.upgrade(options[, callback])`](Dispatcher.md#dispatcherupgradeoptions-callback).
## Instance Events
### Event: `'connect'`
See [Dispatcher Event: `'connect'`](Dispatcher.md#event-connect).
### Event: `'disconnect'`
See [Dispatcher Event: `'disconnect'`](Dispatcher.md#event-disconnect).
### Event: `'drain'`
See [Dispatcher Event: `'drain'`](Dispatcher.md#event-drain).
