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Pools - Resize Pool

Service:
Batch Service
API Version:
2025-06-01

Changes the number of Compute Nodes that are assigned to a Pool.
You can only resize a Pool when its allocation state is steady. If the Pool is already resizing, the request fails with status code 409. When you resize a Pool, the Pool's allocation state changes from steady to resizing. You cannot resize Pools which are configured for automatic scaling. If you try to do this, the Batch service returns an error 409. If you resize a Pool downwards, the Batch service chooses which Compute Nodes to remove. To remove specific Compute Nodes, use the Pool remove Compute Nodes API instead.

POST {endpoint}/pools/{poolId}/resize?api-version=2025-06-01
With optional parameters: 
POST {endpoint}/pools/{poolId}/resize?api-version=2025-06-01&timeOut={timeOut}

URI Parameters

Name In Required Type Description
endpoint
 path True

string (uri)

Batch account endpoint (for example: https://batchaccount.eastus2.batch.azure.com).
poolId
 path True

string

The ID of the Pool to get.
api-version
 query True

string

minLength: 1

The API version to use for this operation.
timeOut
 query

integer (int32)

The maximum time that the server can spend processing the request, in seconds. The default is 30 seconds. If the value is larger than 30, the default will be used instead.".

Request Header

Media Types: "application/json; odata=minimalmetadata"

Name Required Type Description
client-request-id

string

The caller-generated request identity, in the form of a GUID with no decoration such as curly braces, e.g. 9C4D50EE-2D56-4CD3-8152-34347DC9F2B0.
return-client-request-id

boolean

Whether the server should return the client-request-id in the response.
ocp-date

string (date-time-rfc7231)

The time the request was issued. Client libraries typically set this to the current system clock time; set it explicitly if you are calling the REST API directly.
If-Modified-Since

string (date-time-rfc7231)

A timestamp indicating the last modified time of the resource known to the client. The operation will be performed only if the resource on the service has been modified since the specified time.
If-Unmodified-Since

string (date-time-rfc7231)

A timestamp indicating the last modified time of the resource known to the client. The operation will be performed only if the resource on the service has not been modified since the specified time.
If-Match

string

An ETag value associated with the version of the resource known to the client. The operation will be performed only if the resource's current ETag on the service exactly matches the value specified by the client.
If-None-Match

string

An ETag value associated with the version of the resource known to the client. The operation will be performed only if the resource's current ETag on the service does not match the value specified by the client.

Request Body

Media Types: "application/json; odata=minimalmetadata"

Name Type Description
nodeDeallocationOption

BatchNodeDeallocationOption

Determines what to do with a Compute Node and its running task(s) if the Pool size is decreasing. The default value is requeue.
resizeTimeout

string (duration)

The timeout for allocation of Nodes to the Pool or removal of Compute Nodes from the Pool. The default value is 15 minutes. The minimum value is 5 minutes. If you specify a value less than 5 minutes, the Batch service returns an error; if you are calling the REST API directly, the HTTP status code is 400 (Bad Request).
targetDedicatedNodes

integer (int32)

The desired number of dedicated Compute Nodes in the Pool.
targetLowPriorityNodes

integer (int32)

The desired number of Spot/Low-priority Compute Nodes in the Pool.

Responses

Name Type Description
202 Accepted

The request has been accepted for processing, but processing has not yet completed.

Headers

  • DataServiceId: string
  • ETag: string
  • Last-Modified: string
  • client-request-id: string
  • request-id: string
Other Status Codes

BatchError

An unexpected error response.

Security

OAuth2Auth

Type: oauth2
Flow: implicit
Authorization URL: https://login.microsoftonline.com/common/oauth2/v2.0/authorize

Scopes

Name Description
https://batch.core.windows.net//.default

Examples

Pool resize

Sample request

POST {endpoint}/pools/resizePool/resize?api-version=2025-06-01



{
  "targetDedicatedNodes": 1,
  "targetLowPriorityNodes": 0
}

Sample response

Status code:
202

Definitions

Name Description
BatchError

An error response received from the Azure Batch service.
BatchErrorDetail

An item of additional information included in an Azure Batch error response.
BatchErrorMessage

An error message received in an Azure Batch error response.
BatchNodeDeallocationOption

BatchNodeDeallocationOption enums
BatchPoolResizeOptions

Parameters for changing the size of an Azure Batch Pool.

BatchError

Object

An error response received from the Azure Batch service.

Name Type Description
code

string

An identifier for the error. Codes are invariant and are intended to be consumed programmatically.
message

BatchErrorMessage

A message describing the error, intended to be suitable for display in a user interface.
values

BatchErrorDetail[]

A collection of key-value pairs containing additional details about the error.

BatchErrorDetail

Object

An item of additional information included in an Azure Batch error response.

Name Type Description
key

string

An identifier specifying the meaning of the Value property.
value

string

The additional information included with the error response.

BatchErrorMessage

Object

An error message received in an Azure Batch error response.

Name Type Description
lang

string

The language code of the error message.
value

string

The text of the message.

BatchNodeDeallocationOption

Enumeration

BatchNodeDeallocationOption enums

Value Description
requeue

Terminate running Task processes and requeue the Tasks. The Tasks will run again when a Compute Node is available. Remove Compute Nodes as soon as Tasks have been terminated.
terminate

Terminate running Tasks. The Tasks will be completed with failureInfo indicating that they were terminated, and will not run again. Remove Compute Nodes as soon as Tasks have been terminated.
taskcompletion

Allow currently running Tasks to complete. Schedule no new Tasks while waiting. Remove Compute Nodes when all Tasks have completed.
retaineddata

Deprecated, we encourage you to upload task data to Azure Storage in your task and use TaskCompletion instead. Allow currently running Tasks to complete, then wait for all Task data retention periods to expire. Schedule no new Tasks while waiting. Remove Compute Nodes when all Task retention periods have expired.

BatchPoolResizeOptions

Object

Parameters for changing the size of an Azure Batch Pool.

Name Type Description
nodeDeallocationOption

BatchNodeDeallocationOption

Determines what to do with a Compute Node and its running task(s) if the Pool size is decreasing. The default value is requeue.
resizeTimeout

string (duration)

The timeout for allocation of Nodes to the Pool or removal of Compute Nodes from the Pool. The default value is 15 minutes. The minimum value is 5 minutes. If you specify a value less than 5 minutes, the Batch service returns an error; if you are calling the REST API directly, the HTTP status code is 400 (Bad Request).
targetDedicatedNodes

integer (int32)

The desired number of dedicated Compute Nodes in the Pool.
targetLowPriorityNodes

integer (int32)

The desired number of Spot/Low-priority Compute Nodes in the Pool.