Serverless

The serverless feature allows you to create and use databases without worrying about the resource configuration of your cluster. The following figure shows the resource specification changes of common and serverless clusters in scenarios in which the business workloads fluctuate.

The preceding figure provides the following information:

• Common cluster: Low resource utilization during low-demand periods translates into wasted costs, whereas insufficient resources during high-demand periods affect service performance.

• Serverless cluster:

  • Dynamically adjusts resource specifications based on workloads. This improves resource utilization and reduces resource waste.

  • Quickly scales up or down resources based on changing workloads. This ensures performance and service stability even during peak hours.

  • Breaks away from the traditional fixed-resource pricing model by using the pay-as-you-go billing method. Users are charged based on actual resource usage, which results in substantial cost savings.

  • Specifically optimized for high-throughput write scenarios and high-concurrency scenarios. These optimizations combined with elastic scaling capabilities make serverless clusters suitable for businesses that handle large amounts of data and experience fluctuating traffic patterns.

  • Automatically adjusts configurations without the need for manual intervention, which increases operational efficiency and saves time and labor costs.

Overview

The serverless feature provides real-time scaling elasticity for CPU, memory, storage, and network resources. The feature provides vertical resource isolation for network resources, namespaces, and storage space, and on-demand billing for computing and storage resources. This enables the flexible allocation of compute and storage resources based on actual business requirements. This capability enables the cluster to quickly and independently adjust computing and storage capacities in response to fluctuations in workload such as peaks and troughs. As a result, businesses can rapidly respond to changes in workload while optimizing cost efficiency.

Architecture

Serverless feature of a cluster with defined specifications

Serverless feature of a cluster with defined specifications

PolarProxy PolarProxy includes resources with defined specifications and serverless resources. The serverless resources are scaled based on the workloads. The serverless resources are scaled in units of 0.5 PCUs. The number of PCUs added or removed in a scaling activity is positively correlated with the number of PCUs used. Compute nodes The primary node and read-only nodes include the resources with defined specifications and the serverless resources. The resources with defined specifications cannot be scaled, whereas the serverless resources can be scaled based on the workloads. The number of PCUs increases or decreases based on the scaling of the primary node or read-only nodes. Resources are scaled in units of 0.5 PCUs. The number of PCUs added or removed in a scaling activity is positively correlated with the number of PCUs used. You can set the scaling range of a node in PCUs. The system monitors the PCUs of a compute node every second. Storage The storage of the common cluster with defined specifications is used. For more information, see Storage. Note After you enable the serverless feature for an existing cluster with defined specifications, the maximum number of connections to the cluster and the maximum IOPS of the cluster are proportional to the specified value of the Maximum Resources for Single Node parameter.

Benefits

The serverless feature can dynamically scale cluster resources in seconds based on real-time business loads. The serverless feature provides the following benefits:

• High availability

  The multi-node architecture ensures high availability and stability of serverless clusters.

• High scalability

  • Wide scaling range: Automatic vertical scaling and horizontal scaling are supported.

  • Scaling within seconds: When your workloads increase, workload detection is completed in 5 seconds and cluster resources are scaled out within 1 second. If your workloads decrease, cluster resources are automatically released by tier.

• Strong data consistency

  The serverless feature supports global consistency and ensures strong data consistency within the cluster. Data written to the cluster is immediately available for reading on read-only nodes with performance almost the same as the performance in weak consistency mode.

  Note

  By default, the global consistency feature is disabled. You can manually enable the feature on the cluster endpoint. For more information, see Global consistency.

• Cost-effectiveness

  Serverless clusters are billed in PCUs based on the pay-as-you-go billing method. Costs can be reduced by up to 80%.

• Zero O&M

  The PolarDB serverless team is responsible for all operations and maintenance work, such as system upgrades, system deployment, scaling, and alert processing. These operations are performed in the background and do not affect the services that are running in the system. This ensures continuous service delivery and allows you to focus on developing your business.

Scenarios

• Scenarios in which workloads dramatically fluctuate

• Scenarios that handle inconsistent and unpredictable workloads, such as IoT and edge computing

• Scenarios that need to reduce O&M costs and improve O&M efficiency

• Scenarios that need to satisfy fluctuation requirements based on existing PolarDB clusters.

Supported versions

Your PolarDB for PostgreSQL (Compatible with Oracle) cluster runs the following database engine version:

PolarDB for PostgreSQL (Compatible with Oracle) 2.0 whose revision version is 2.0.14.27.0 or later

Billing

The fees of a serverless-enabled cluster with defined specifications consists of the fees for the cluster with defined specifications and the fees related to the serverless feature. For information about the fees of the cluster with defined specifications, see Billable items. For information about the fees related to the serverless feature, see Billing.