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
-
During a scale-in, the data on the to-be-removed nodes needs to be migrated to the remaining nodes. The timeout for data migration per node is 48 hours. Scale-in will fail if this timeout expires. When the cluster has large quantities of data, you are advised to manually adjust the data migration rate and avoid performing the migration during peak hours.
-
Yearly/Monthly clusters do not support the removal of specified nodes by calling this API.
-
All mission-critical data has been backed up before a cluster scale-in. This is to prevent data loss.
-
Only Elasticsearch and OpenSearch clusters support this option.
-
During a scale-in, the data on the to-be-removed nodes needs to be migrated to the remaining nodes. The timeout for data migration per node is 48 hours. Scale-in will fail if this timeout expires. When the cluster has large quantities of data, you are advised to manually adjust the data migration rate and avoid performing the migration during peak hours.
-
For a cluster without master nodes, scale-in is allowed only if the number of data nodes plus cold data nodes is at least three. During a scale-in, you can only remove less than half of the data nodes plus cold data nodes, and the remaining number must be greater than the maximum number of index replicas.
-
For a cluster with master nodes, scale-in is allowed only if the cluster has at least two data nodes. During a scale-in, you can only remove less than half of the cluster's master nodes.
-
After the scale-in, the cluster nodes' disk usage must be less than 80%.
-
After the scale-in, there has to be at least one of each type of node in each AZ. For a cross-AZ cluster, the difference between the numbers of the same-type nodes in different AZs cannot exceed 1.
Calling Method
For details, see Calling APIs.
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.
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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 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.
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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 = 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.
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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.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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