Coordinator nodes of AnalyticDB for PostgreSQL are used to manage the endpoints, status, and task execution of instances. If your instance has insufficient resources, you can change the specifications of coordinator node resources and scale compute nodes to improve the overall instance performance such as the number of connections and read and write performance.
Usage notes
The change to the specifications of coordinator node resources may cause the current SQL statements to be interrupted. The SQL statements cannot be resumed even after the change is complete. Perform this operation during an appropriate period of time.
Suggestions on changing specifications of coordinator node resources
In most cases, the default specifications of coordinator node resources can meet your business requirements. However, if your business scenario involves a large number of connections or your transaction processing workloads require low latency and high throughput, you may need higher specifications of coordinator node resources.
You can change specifications of coordinator node resources in the following aspects:
Instance monitoring data
You can view the usage of coordinator node resources on the Coordinator Node tab of the Monitoring and Alerts page. If the CPU utilization or memory usage of coordinator nodes remains persistently high, you can upgrade the specifications of coordinator node resources.
Typical workloads
For a TPC-C test of typical transaction processing workloads, the test performance varies based on the specifications of coordinator node resources. For more information, see TPC-C.
The following table provides an example of performance parameters for an instance that has 32 compute nodes of 4 cores and 32 GB memory.
Coordinator node resources (CUs)
Concurrency
Performance (tpmC)
Linear ratio
8
32
18361.97
1.0
16
64
33536.84
1.83
32
128
58787.01
3.20
The preceding test result shows that higher specifications of coordinator node resources can significantly improve system performance for transaction processing workloads. However, an increase in the specifications of coordinator node resources to more than 32 compute units (CUs) hardly improves the performance of workloads. This is because the disk bandwidth of compute nodes reaches the upper limit in this case. Therefore, we recommend that you do not set the specifications of coordinator node resources to more than 32 CUs. If you require more than 32 CUs of coordinator node resources, contact technical support of AnalyticDB for PostgreSQL.
Add coordinator node resources
- Log on to the AnalyticDB for PostgreSQL console.
- In the upper-left corner of the console, select a region.
- Find the instance that you want to manage and click the instance ID.
In the upper-right corner of the Basic Information page, choose .
For an instance in Serverless mode, select I am aware of the impact of this operation and agree to continue it. and click OK in the Info dialog box.
ImportantAfter you submit a specification change request, the current SQL statements are interrupted. The SQL statements cannot be resumed even after the change is complete.
On the Upgrade/Downgrade page, select a value for Coordinator Node Resources, read and select the Terms of Service, and then click Buy Now.
ImportantYou are charged for coordinator node resources of more than 8 CUs on a pay-as-you-go basis. For more information, see Pricing.
Return to the Instances page and wait for the instance state to change to Running.
Remove coordinator node resources
- Log on to the AnalyticDB for PostgreSQL console.
- In the upper-left corner of the console, select a region.
- Find the instance that you want to manage and click the instance ID.
In the upper-right corner of the Basic Information page, choose .
For an instance in Serverless mode, select I am aware of the impact of this operation and agree to continue it. and click OK in the Info dialog box.
ImportantAfter you submit a specification change request, the current SQL statements are interrupted. The SQL statements cannot be resumed even after the change is complete.
On the Upgrade/Downgrade page, select a value for Coordinator Node Resources, read and select the Terms of Service, and then click Buy Now.
Return to the Instances page and wait for the instance state to change to Running.