PolarDB-X is a distributed cluster of nodes, each handling SQL routing, data merging, and data aggregation. You can scale node specifications up during peak hours to handle higher QPS, or scale down during off-peak hours to reduce resource costs.
Prerequisites
Before you begin, make sure that you have:
A PolarDB-X 2.0 instance in the PolarDB-X console
An application that supports automatic reconnection to the database
Impacts of changing node specifications
Changing node specifications causes brief connection interruptions between your application and the instance. Keep the following in mind before you proceed:
Transient disconnections: Connections drop momentarily during the change. Make sure your application reconnects automatically.
New nodes and persistent connections: When you upgrade, additional nodes are added. If your application uses persistent connections (for example, through an Elastic Compute Service (ECS) instance connected directly to PolarDB-X), those new nodes do not receive traffic immediately. To route traffic to the new nodes, restart your ECS instances in phases: start with the instances handling the smallest workload, verify that service is running as expected, then restart the remaining instances. To avoid this issue altogether, use the Druid connection pool. For more information, see Configure a connection pool for an application to connect to a PolarDB-X instance.
Edition limits: Enterprise Edition instances support specification changes for both compute nodes and data nodes. Standard Edition instances support specification changes for data nodes only.
Tip: Test specification changes in a non-production environment before applying them to production. This helps you assess the impact before it affects live traffic.
Change node specifications
Log on to the PolarDB-X console.
In the top navigation bar, select the region where the instance is deployed.
On the Instances page, click the PolarDB-X 2.0 tab.
Find the instance and click Upgrade or Downgrade in its Actions column.
On the Upgrade/Downgrade or Downgrade page, select the target specifications for the nodes.
Set Switch Mode.
Click Buy Now.
Click Sign and Purchase.
The instance shows a status of Upgrading or Downgrading in the console until the operation is complete.
What's next
To configure automatic reconnection for your application, see Configure a connection pool for an application to connect to a PolarDB-X instance.