Manage coordinator node resources

Considerations

Changing coordinator node specifications interrupts any ongoing SQL queries, which cannot be resumed after the change is complete.

Selecting coordinator node specifications

While the default coordinator node specifications are sufficient for most scenarios, you may require higher specifications if your business handles a large number of concurrent connections or runs a transaction processing (TP) workload that demands low latency and high throughput.

Consider the following factors when deciding whether to adjust your coordinator node specifications.

• Instance monitoring data

  You can view the resource usage of the coordinator node on the Coordinator Nodes tab of the Monitoring and Alerts page in the console. If the CPU or memory utilization of the coordinator node remains high for an extended period, you should consider upgrading its specifications.

• Typical workloads

  For a classic TP workload like TPC-C (for more information, see TPC-C introduction), coordinator node specifications directly impact test performance.

  The following table shows the performance parameters for an instance with 32 compute nodes, each with 4 CPU cores and 32 GB of memory. The values are for reference only.

  Coordinator resources (CU)	Concurrency	Performance (tpmC)	Linear ratio
  8	32	18361.97	1.0
  16	64	33536.84	1.83
  32	128	58787.01	3.20

  The test results show that for a TP workload, increasing the coordinator node specifications can significantly improve system performance. However, performance gains diminish beyond 32 compute units (CUs) because the cloud disk bandwidth of the compute nodes becomes the bottleneck. Therefore, we generally recommend not exceeding 32 CUs for the coordinator node. If your workload requires more than 32 CUs, contact official support for AnalyticDB for PostgreSQL.

Add coordinator node resources

1. Log on to the AnalyticDB for PostgreSQL console.
2. In the upper-left corner of the console, select a region.
3. Find the instance that you want to manage and click the instance ID.

4. In the upper-right corner of the Basic Information page, choose Manage Instance > Change Master Node Configurations > Add Coordinator Node Resources.

   For an instance in Info, select I am aware of the impact of this operation and agree to continue it. in the dialog box that appears, and then click OK.

   Important

   This operation interrupts any ongoing SQL queries, and they cannot be resumed after the change is complete.

5. On the Upgrade/Downgrade page, select the desired coordinator node resources, agree to the terms of service, and click Buy Now.

   Important

   Coordinator node resources exceeding 8 CUs are billed on a pay-as-you-go basis. For billing details, see Pricing.

6. Return to the Instances page and wait until the instance status changes to Running.

Remove coordinator node resources

1. Log on to the AnalyticDB for PostgreSQL console.
2. In the upper-left corner of the console, select a region.
3. Find the instance that you want to manage and click the instance ID.

4. In the upper-right corner of the Basic Information page, choose Manage Instance > Change Master Node Configurations > Remove Coordinator Node Resources.

   For an instance in Info, select I am aware of the impact of this operation and agree to continue it. in the dialog box that appears, and then click OK.

   Important

   This operation interrupts any ongoing SQL queries, and they cannot be resumed after the change is complete.

5. On the Upgrade/Downgrade page, select the desired coordinator node resources, agree to the terms of service, and click Buy Now.

6. Return to the Instances page and wait until the instance status changes to Running.