Scaling In a Cluster by Removing a Specific Node
Function
If a cluster has excess capacity due to off-peak traffic or reduced data volume, you can reduce its nodes to cut costs.
Constraints
-
Scale-in involves data migration. The timeout threshold for data migration on a single node is 48 hours. If this threshold is exceeded, the scale-in operation fails. If the cluster contains a large amount of data, it is recommended that you manually adjust the data migration rate and avoid performing the operation during peak service hours.
-
Before performing scale-in, it is recommended that you back up all critical data to avoid data loss.
-
Scale-in involves data migration. The timeout threshold for data migration on a single node is 48 hours. If this threshold is exceeded, the scale-in operation fails. If the cluster contains a large amount of data, it is recommended that you manually adjust the data migration rate and avoid performing the operation during peak service hours.
-
For clusters without master nodes: scale-in is supported only when the total number of data nodes and cold data nodes is greater than or equal to 3. In a single scale-in operation, the total number of data nodes and cold data nodes to be removed must be less than half of the total number before scale-in. After scale-in, the total number of data nodes and cold data nodes must be greater than the maximum number of index replicas.
-
For clusters with master nodes: scale-in is supported only when the number of data nodes is greater than or equal to 2. In a single scale-in operation, the number of master nodes to be removed must be less than half of the number of master nodes before scale-in.
-
After scale-in, at least one instance of each node type must remain in each AZ. For cross-AZ clusters, the number of same-type nodes in different AZs must not differ by more than 1. For clusters with two AZs, at least two data nodes (ess) or cold data nodes (ess-cold) must be deployed in each AZ.
- Yearly/Monthly clusters do not support scale-in on specified nodes through this API.
Calling Method
For details, see Calling APIs.
Authorization Information
Each account has all the permissions required to call all APIs, but IAM users must be assigned the required permissions.
- If you are using role/policy-based authorization, see Permissions Policies and Supported Actions for details on the required permissions.
- If you are using identity policy-based authorization, the following identity policy-based permissions are required.
URI
POST /v1.0/{project_id}/clusters/{cluster_id}/node/offline
| 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 to be scaled 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
| Parameter | Mandatory | Type | Description |
|---|---|---|---|
| migrate_data | No | String | Definition: Whether to migrate data. Value range:
Default value: true |
| shrink_nodes | Yes | Array of strings | Definition: ID of the node to be removed. Constraints: N/A Value range: Obtain the ID attribute in instances by referring to Querying Cluster Details. Default value: N/A |
| agency_name | No | String | Definition: Agency name that grants the current account the permission to access and use OBS. To store snapshots to an OBS bucket, you must have the required OBS access permissions. 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 |
Response Parameters
Status code: 200
Request succeeded.
None
Example Requests
Scale in a cluster by removing specified nodes.
POST https://{Endpoint}/v1.0/{project_id}/clusters/4f3deec3-efa8-4598-bf91-560aad1377a3/node/offline
{
"shrink_nodes" : [ "2077bdf3-b90d-412e-b460-635b9b159c11" ],
"migrate_data" : "true"
} Example Responses
None
SDK Sample Code
The SDK sample code is as follows.
Java
Scale in a cluster by removing specified nodes.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 | 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 UpdateShrinkNodesSolution { 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(); UpdateShrinkNodesRequest request = new UpdateShrinkNodesRequest(); request.withClusterId("{cluster_id}"); ShrinkNodesReq body = new ShrinkNodesReq(); List<String> listbodyShrinkNodes = new ArrayList<>(); listbodyShrinkNodes.add("2077bdf3-b90d-412e-b460-635b9b159c11"); body.withShrinkNodes(listbodyShrinkNodes); body.withMigrateData("true"); request.withBody(body); try { UpdateShrinkNodesResponse response = client.updateShrinkNodes(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 removing specified nodes.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 | # 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 = UpdateShrinkNodesRequest() request.cluster_id = "{cluster_id}" listShrinkNodesbody = [ "2077bdf3-b90d-412e-b460-635b9b159c11" ] request.body = ShrinkNodesReq( shrink_nodes=listShrinkNodesbody, migrate_data="true" ) response = client.update_shrink_nodes(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 removing specified nodes.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 | 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.UpdateShrinkNodesRequest{} request.ClusterId = "{cluster_id}" var listShrinkNodesbody = []string{ "2077bdf3-b90d-412e-b460-635b9b159c11", } migrateDataShrinkNodesReq:= "true" request.Body = &model.ShrinkNodesReq{ ShrinkNodes: listShrinkNodesbody, MigrateData: &migrateDataShrinkNodesReq, } response, err := client.UpdateShrinkNodes(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.
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