PolarDB:Manage data nodes

Background information

PolarDB-X allows you to separately upgrade or downgrade storage resource pools and data nodes. This enables fine-grained control and resource isolation for data nodes, meets the requirements of different business scenarios, and optimizes resource utilization.

• Storage resource pools organize data nodes into distinct, non-overlapping groups, ensuring that each data node belongs to only one pool. You can add a data node to or remove a data node from a storage resource pool. In scenarios in which storage resource isolation is required (such as a SAAS multi-tenant scenario), you can create a custom storage resource pool for each tenant to isolate storage resources among tenants. By default, PolarDB-X provides two storage resource pools: the default storage resource pool _default and the recycle bin resource pool _recycle.

• You can associate objects such as databases, tables, and partitions in a database with different storage resource pools by using the LOCALITY attribute.

Each data node requires different resources based on the data distribution. PolarDB-X allows you to separately upgrade and downgrade each data node. This improves the overall resource utilization.

Precautions

• To use storage resource pools, make sure that your PolarDB-X instance runs V5.4.18-17066805 or later. By default, the original data nodes are assigned to the_default storage resource pool after a PolarDB-X instance of an earlier version is upgraded to V5.4.18-17066805.

• The data node management feature is unavailable for read-only instances.

• After you change the configuration of a single data node in a PolarDB-X instance, the configurations of the data nodes in the PolarDB-X instance are different. Pay attention to the following points for operations on the instance:

  • You cannot change the overall configuration of the PolarDB-X instance, but can change the configurations of compute nodes and data nodes.

  • You cannot downgrade the PolarDB-X instance by changing the number of data nodes. To downgrade the PolarDB-X instance, you can only delete data nodes on the Data Node Management page.

Procedure

Create a custom storage resource pool

In scenarios in which storage resource isolation is required (such as a SAAS multi-tenant scenario), you can create a custom storage resource pool for each tenant to isolate storage resources among tenants.

1. Log on to the PolarDB-X console.

2. In the top navigation bar, select the region in which your instance is deployed.

3. On the Instances page, click the PolarDB-X 2.0 tab.

4. Find the instance and click the instance name.

5. In the left-side navigation pane, click Data Node Management.

6. On the right side of the page, click Create Resource Pool.

7. In the Create Resource Pool dialog box, enter a storage pool name in the Resource Pool Name field. You can expand the Advanced Settings option and select data nodes in the_recyle storage resource pool to associate them with the new custom storage resource pool. By default, no data node is selected. If you choose not to select data nodes, you can add nodes after the custom storage resource pool is created.

8. Click OK. The custom storage resource pool is created.

Change the configuration of a data node

1. Log on to the PolarDB-X console.

2. In the top navigation bar, select the region in which your instance is deployed.

3. On the Instances page, click the PolarDB-X 2.0 tab.

4. Find the instance and click the instance name.

5. In the left-side navigation pane, click Data Node Management.

6. In the Data Node List section, find the node whose configuration you want to change and click Change Configurations in the Actions column.

   Note

   To change the configurations of multiple data nodes at the same time, select the data nodes and click Batch Configuration Change in the upper-right corner.

7. In the Data Node Configuration Change dialog box, select the new configuration and switching mode.

8. Click Pay to commit the Change Configurations operation.

Add a data node

1. Log on to the PolarDB-X console.

2. In the top navigation bar, select the region in which your instance is deployed.

3. On the Instances page, click the PolarDB-X 2.0 tab.

4. Find the instance and click the instance name.

5. In the left-side navigation pane, click Data Node Management.

6. Configure the policy to add nodes.

   1. If your instance version does not support the storage resource pool feature, click Add Node in the upper-right corner.

   2. If your instance supports the storage resource pool feature, click Add Node on the tab of the destination storage resource pool to add data nodes to the storage pool.

   Note

   By default, new nodes are added to the_default storage resource pool if no custom storage pool is created for your instance.

7. In the dialog box that appears, select the number of data nodes that you want to add and click Buy Now.

Release a data node

1. Log on to the PolarDB-X console.

2. In the top navigation bar, select the region in which your instance is deployed.

3. On the Instances page, click the PolarDB-X 2.0 tab.

4. Find the instance and click the instance name.

5. In the left-side navigation pane, click Data Node Management.

6. In the Data Node List section, find the node that you want to release and click Release Node in the Actions column.

   Note

   • To release multiple data nodes at the same time, select the data nodes and click Delete Node in the upper-right corner.

   • Some data nodes are the default storage nodes of centralized tables. You can change the configurations of these data nodes but cannot release these data nodes. The Release Node button for these data nodes is dimmed.