Function

This API is used to remove instances of specific types and reduce instance storage capacity in a cluster.

All mission-critical data has been backed up before a cluster scale-in. This is to prevent data loss.

Calling Method

For details, see Calling APIs.

URI

POST /v1.0/extend/{project_id}/clusters/{cluster_id}/role/shrink

**Table 1** Path Parameters
Parameter	Mandatory	Type	Description
project_id	Yes	String	Definition: Project ID. For details about how to obtain the project ID and name, see Obtaining the Project ID and Name. Constraints: N/A Value range: Project ID of the account. Default value: N/A
cluster_id	Yes	String	Definition: ID of the cluster you want to scale in. For details about how to obtain the cluster ID, see Obtaining the Cluster ID. Constraints: N/A Value range: Cluster ID. Default value: N/A

Request Parameters

**Table 2** Request body parameters
Parameter	Mandatory	Type	Description
shrink	Yes	Array of ShrinkNodeReq objects	Parameter description: Type and quantity of nodes you want to scale in.
agency_name	No	String	Definition: Agency name. You can create an agency to allow CSS to call other cloud services. Constraints: VPC permissions required by the agency: "vpc:subnets:get","vpc:ports:". This parameter is mandatory when the new IAM plane is connected. This parameter is optional when the old IAM plane is connected. Value range: N/A Default value*: N/A
operation_type	No	String	Definition: Operation type. Constraints: N/A Value range: vm: Reduce nodes. [- volume: Reduce the disk size.] (tag:white) Default value: vm
cluster_load_check	No	Boolean	Definition: Whether to check the cluster load. Constraints: N/A Value range: true: enable cluster load check. true: skip cluster load check. Default value: true

**Table 3** ShrinkNodeReq
Parameter	Mandatory	Type	Description
reducedNodeNum	Yes	Integer	Definition: Number of nodes you want to reduce. Constraints: After the scale-in, there has to be at least one node of each type in each AZ. In a cross-AZ cluster, the difference between the numbers of same-type nodes in different AZs cannot exceed 1. For a cluster with no Master nodes, the number of removed data nodes (including cold data nodes and other types of nodes) in a scale-in must be fewer than half of the number of the original data nodes, and the number of remaining data nodes after a scale-in must be greater than the maximum number of index replicas. For a cluster with master nodes, the number of removed master nodes in a scale-in must be fewer than half of the number of the original master nodes. After scale-in, there has to be an odd number of master nodes, and there has to be at least three of them. Value range: See Constraints. Default value: N/A
type	Yes	String	Definition: Node type. Constraints: N/A [If operation_type is set to volume, this parameter cannot be set to ess-client or ess-master.] (tag:white) Value range: ess: data node ess-cold: cold data node ess-client: client node ess-master: master node Default value: N/A

Response Parameters

Status code: 200

Request succeeded.

None

Example Requests

Scale in a cluster by specifying the node type and the number of nodes to be removed.

POST https://{Endpoint}/v1.0/extend/{project_id}/clusters/4f3deec3-efa8-4598-bf91-560aad1377a3/role/shrink

{
  "shrink" : [ {
    "type" : "ess",
    "reducedNodeNum" : 1
  } ]
}

Example Responses

None

Status Codes

Status Code	Description
200	Request succeeded.
400	Invalid request. Modify the request before retry.
409	The request could not be completed due to a conflict with the current state of the resource. The resource that the client attempts to create already exists, or the update request fails to be processed because of a conflict.
412	The server did not meet one of the preconditions contained in the request.

Error Codes

See Error Codes.

Scaling In Nodes of a Specific Type