Help Center/ Cloud Search Service/ API Reference/ API V1/ Cluster Management/ Scaling In Nodes of a Specific Type
Updated on 2025-08-15 GMT+08:00

Scaling In Nodes of a Specific Type

Function

This API is used to remove instances of specific types and reduce instance storage capacity in a cluster. Yearly/Monthly clusters do not support the removal of specified node types by calling this API.

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. The value can be vm or volume. The default value is vm.

Constraints:

N/A

Value range:

vm: Reduce nodes.

volume: Reduce the disk size.

Default value:

vm

cluster_load_check

No

Boolean

Definition:

Whether to check the cluster load. The value can be true or false. The default value is true.

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.

  • 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.

type

Yes

String

Parameter description:

Node type.

Options:

  • ess: data node

  • ess-cold: cold data node

  • ess-client: client node

  • ess-master: master node

new_disk_size

No

Integer

Definition:

New disk size.

Constraints:

N/A

Value range:

  1. This parameter is valid only when operationType is set to volume. The disk capacity after scale-in must be a multiple of 20 and within the storage capacity range supported by the current node specifications.

Response Parameters

Status code: 200

Request succeeded.

None

Example Requests

Scale in a cluster by scaling in specified type of nodes.

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

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

Example Responses

None

SDK Sample Code

The SDK sample code is as follows.

Java

Scale in a cluster by scaling in specified type of nodes.

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package com.huaweicloud.sdk.test;

import com.huaweicloud.sdk.core.auth.ICredential;
import com.huaweicloud.sdk.core.auth.BasicCredentials;
import com.huaweicloud.sdk.core.exception.ConnectionException;
import com.huaweicloud.sdk.core.exception.RequestTimeoutException;
import com.huaweicloud.sdk.core.exception.ServiceResponseException;
import com.huaweicloud.sdk.css.v1.region.CssRegion;
import com.huaweicloud.sdk.css.v1.*;
import com.huaweicloud.sdk.css.v1.model.*;

import java.util.List;
import java.util.ArrayList;

public class UpdateShrinkClusterSolution {

    public static void main(String[] args) {
        // The AK and SK used for authentication are hard-coded or stored in plaintext, which has great security risks. It is recommended that the AK and SK be stored in ciphertext in configuration files or environment variables and decrypted during use to ensure security.
        // In this example, AK and SK are stored in environment variables for authentication. Before running this example, set environment variables CLOUD_SDK_AK and CLOUD_SDK_SK in the local environment
        String ak = System.getenv("CLOUD_SDK_AK");
        String sk = System.getenv("CLOUD_SDK_SK");
        String projectId = "{project_id}";

        ICredential auth = new BasicCredentials()
                .withProjectId(projectId)
                .withAk(ak)
                .withSk(sk);

        CssClient client = CssClient.newBuilder()
                .withCredential(auth)
                .withRegion(CssRegion.valueOf("<YOUR REGION>"))
                .build();
        UpdateShrinkClusterRequest request = new UpdateShrinkClusterRequest();
        request.withClusterId("{cluster_id}");
        ShrinkClusterReq body = new ShrinkClusterReq();
        List<ShrinkNodeReq> listbodyShrink = new ArrayList<>();
        listbodyShrink.add(
            new ShrinkNodeReq()
                .withReducedNodeNum(1)
                .withType("ess")
        );
        body.withShrink(listbodyShrink);
        request.withBody(body);
        try {
            UpdateShrinkClusterResponse response = client.updateShrinkCluster(request);
            System.out.println(response.toString());
        } catch (ConnectionException e) {
            e.printStackTrace();
        } catch (RequestTimeoutException e) {
            e.printStackTrace();
        } catch (ServiceResponseException e) {
            e.printStackTrace();
            System.out.println(e.getHttpStatusCode());
            System.out.println(e.getRequestId());
            System.out.println(e.getErrorCode());
            System.out.println(e.getErrorMsg());
        }
    }
}

Python

Scale in a cluster by scaling in specified type of nodes.

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# coding: utf-8

import os
from huaweicloudsdkcore.auth.credentials import BasicCredentials
from huaweicloudsdkcss.v1.region.css_region import CssRegion
from huaweicloudsdkcore.exceptions import exceptions
from huaweicloudsdkcss.v1 import *

if __name__ == "__main__":
    # The AK and SK used for authentication are hard-coded or stored in plaintext, which has great security risks. It is recommended that the AK and SK be stored in ciphertext in configuration files or environment variables and decrypted during use to ensure security.
    # In this example, AK and SK are stored in environment variables for authentication. Before running this example, set environment variables CLOUD_SDK_AK and CLOUD_SDK_SK in the local environment
    ak = os.environ["CLOUD_SDK_AK"]
    sk = os.environ["CLOUD_SDK_SK"]
    projectId = "{project_id}"

    credentials = BasicCredentials(ak, sk, projectId)

    client = CssClient.new_builder() \
        .with_credentials(credentials) \
        .with_region(CssRegion.value_of("<YOUR REGION>")) \
        .build()

    try:
        request = UpdateShrinkClusterRequest()
        request.cluster_id = "{cluster_id}"
        listShrinkbody = [
            ShrinkNodeReq(
                reduced_node_num=1,
                type="ess"
            )
        ]
        request.body = ShrinkClusterReq(
            shrink=listShrinkbody
        )
        response = client.update_shrink_cluster(request)
        print(response)
    except exceptions.ClientRequestException as e:
        print(e.status_code)
        print(e.request_id)
        print(e.error_code)
        print(e.error_msg)

Go

Scale in a cluster by scaling in specified type of nodes.

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package main

import (
	"fmt"
	"github.com/huaweicloud/huaweicloud-sdk-go-v3/core/auth/basic"
    css "github.com/huaweicloud/huaweicloud-sdk-go-v3/services/css/v1"
	"github.com/huaweicloud/huaweicloud-sdk-go-v3/services/css/v1/model"
    region "github.com/huaweicloud/huaweicloud-sdk-go-v3/services/css/v1/region"
)

func main() {
    // The AK and SK used for authentication are hard-coded or stored in plaintext, which has great security risks. It is recommended that the AK and SK be stored in ciphertext in configuration files or environment variables and decrypted during use to ensure security.
    // In this example, AK and SK are stored in environment variables for authentication. Before running this example, set environment variables CLOUD_SDK_AK and CLOUD_SDK_SK in the local environment
    ak := os.Getenv("CLOUD_SDK_AK")
    sk := os.Getenv("CLOUD_SDK_SK")
    projectId := "{project_id}"

    auth := basic.NewCredentialsBuilder().
        WithAk(ak).
        WithSk(sk).
        WithProjectId(projectId).
        Build()

    client := css.NewCssClient(
        css.CssClientBuilder().
            WithRegion(region.ValueOf("<YOUR REGION>")).
            WithCredential(auth).
            Build())

    request := &model.UpdateShrinkClusterRequest{}
	request.ClusterId = "{cluster_id}"
	var listShrinkbody = []model.ShrinkNodeReq{
        {
            ReducedNodeNum: int32(1),
            Type: "ess",
        },
    }
	request.Body = &model.ShrinkClusterReq{
		Shrink: listShrinkbody,
	}
	response, err := client.UpdateShrinkCluster(request)
	if err == nil {
        fmt.Printf("%+v\n", response)
    } else {
        fmt.Println(err)
    }
}

More

For SDK sample code of more programming languages, see the Sample Code tab in API Explorer. SDK sample code can be automatically generated.

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.