Managing Nodes

Overview

On the Node Management page, you can view the node list of the current cluster, add new nodes to or remove nodes from it, and view the node usage, status, flavor, and AZ. In addition, you can click in the Node Alias column of a specified node to add or modify the node alias.

This function allows you to add nodes in batches for scale-out in advance so that the scale-out does not affect cluster services. To add 180 nodes, add them in three batches of 60 nodes each. If any nodes fail to be added, retry adding them. Once all 180 nodes are added, use them for scaling out.

Figure 1 Managing nodes

Notes and Constraints

• This feature is supported only in 8.1.1.200 or later cluster versions.
• Nodes can be added only when no other task is running on the management side.
• The storage size of a new node must be the same as that of each of the existing nodes in the cluster.
• An added node, typically for scaling out, is referred to as an idle node. It starts incurring charges once added. You are advised to only add nodes when needed and promptly use them for scaling out.
• The anti-affinity rule requires adding nodes in multiples of the cluster ring size. For example, if the cluster ring size is 3, you must add nodes in an integer multiple of 3.
• In the anti-affinity deployment mode, when a node is idle and fails due to power-off or other causes, it makes other nodes in its server group unavailable. In this case, you should remove and re-add the failed node.
• The anti-affinity rule dictates that, if a node fails to be added and is rolled back, other nodes that are being added in the same server group will also be rolled back.
• Nodes can be removed only when no other task is running on the management side.
• Only nodes whose resource status is Idle can be removed. Nodes that are in use cannot be removed.
• In anti-affinity deployment, nodes are removed by cluster ring. For example, if the cluster ring is 3, when you remove a node, other nodes in the same ring will be automatically selected and displayed.
• In a yearly/monthly cluster during the grace period or retention period, nodes cannot be deleted. You can release nodes on the Renewals page of the Billing Center.

Adding Nodes

1. Log in to the DWS console.
2. Choose Cluster > Cluster List. All clusters are displayed by default.
3. Click the name of the target cluster. On the displayed Cluster Information page, choose Node Management.
4. Click Add Node, enter the number of idle nodes to be added, and click Next: Confirm.

   If you create a BMS cluster, contact technical support to add you to the whitelist for cross-flavor scale-out. After you are whitelisted, Resource Flavor will be displayed on the Add Node page.

   If the IP addresses of the original subnet are insufficient, idle nodes in other subnets can be added.

   In yearly/monthly mode, the time remaining and the expiration time are displayed.

   Figure 2 Adding a node
   

5. Click Submit. In the displayed dialog box, click OK. The node management page is displayed. Nodes that fail to be added are automatically rolled back and recorded in the failure list.

Removing Nodes

1. Log in to the DWS console.
2. Choose Cluster > Cluster List. All clusters are displayed by default.
3. Click the name of the target cluster. On the displayed Cluster Information page, choose Node Management.
4. Select the node to be deleted and click Delete Node.
5. (Yearly/Monthly billing mode) The page for deletion confirmation is displayed.
6. Enter DELETE or click Auto Enter in the displayed dialog box, and click OK. The node is no longer displayed on the Node Management page.