Scaling in a Cluster

Prerequisites

The cluster is in the Available state and has no ongoing task.

Constraints

• Only the number of nodes can be modified during cluster scale-in. The node specifications and node storage capacity cannot be modified.
• If you change the number and storage capacity of a specified type of node, nodes in other types will not be changed.
• Ensure that the disk usage after scale-in is less than 80% and each AZ of each node type has at least one node.
• When scaling in a cluster, the data in the node to be deleted is migrated to other nodes. The timeout threshold for data migration is five hours. If data migration is not complete within 5 hours, the cluster scale-in fails. You are advised to perform scale-in for multiple times when the cluster has huge amounts of data.
• The quota of nodes in different types varies. For details, see Table 1.

  Table 1 Number of nodes in different types

  Node Type	Number
  ess	ess: 1-32
  ess, ess-master	ess: 1-200 ess-master: an odd number ranging from 3 to 9
  ess, ess-client	ess: 1-32 ess-client: 1-32
  ess, ess-cold	ess: 1-32 ess-cold: 1-32
  ess, ess-master, ess-client	ess: 1-200 ess-master: an odd number ranging from 3 to 9 ess-client: 1-32
  ess, ess-master, ess-cold	ess: 1-200 ess-master: an odd number ranging from 3 to 9 ess-cold: 1-32
  ess, ess-client, ess-cold	ess: 1-32 ess-client: 1-32 ess-cold: 1-32
  ess, ess-master, ess-client, ess-cold	ess: 1-200 ess-master: an odd number ranging from 3 to 9 ess-client: 1-32 ess-cold: 1-32
  Details about the four node types: ess: the default node type that is mandatory for cluster creation. The other three node types are optional. ess-master: master node ess-client: client node ess-cold: cold data node

Procedure

1. Log in to the CSS management console.
2. In the navigation tree on the left, choose Clusters > Logstash. The cluster management page is displayed.
3. Choose More > Modify Configuration in the Operation column of the target cluster. The Modify Configuration page is displayed.
4. On the Modify Configuration page, choose the Scale Cluster tab and click Scale in to set parameters.
   • Action: Select Scale in.
   • Resources: The changed amount of resources.
   • Agency: Select an IAM agency to grant the current account the permission to switch AZs.

     If no agencies are available, click Create IAM Agency to go to the IAM console and create an agency.

     

     The selected agency must be assigned the Tenant Administrator or VPC Administrator policy.

   • Nodes: The number of the default data nodes. For details about the value range that can be changed, see Table 1.
   Figure 1 Scaling in a cluster
   
5. Click Next.
6. Confirm the information and click Submit.
7. Click Back to Cluster List to switch to the Clusters page. The Task Status is Scaling in. When Cluster Status changes to Available, the cluster has been successfully scaled in.