Fixed compute unit (FCU)

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ApsaraDB for PolarDB provides Compute Plans to cover the cost of fixed-specification compute nodes in pay-as-you-go clusters, which helps lower your expenses.

Notes

  • A fixed-specification compute package's purchase and unsubscription only affect billing and do not affect the normal operation of your services.

  • A fixed-spec compute package is not region-specific. It automatically covers the fees for fixed-spec compute node resources in pay-as-you-go clusters across all regions.

  • If the remaining capacity of a fixed-spec compute package is insufficient, any excess usage is billed on a pay-as-you-go basis.

  • You cannot renew, upgrade, or downgrade fixed-spec compute packages. If a fixed-spec compute package has insufficient capacity, is about to expire, or has expired, you can purchase a new one. The capacities of multiple packages are stacked.

  • After you purchase a fixed-specification compute package, the fixed-specification resources of compute nodes in a pay-as-you-go cluster are no longer charged on an hourly basis. Instead, usage is deducted from the fixed-specification compute package on an hourly basis based on your compute consumption (CUH, or units).

Pricing

PolarDB uses CU (Capacity Unit) to measure the computing power of nodes in a cluster. The total capacity of a compute package is measured in CU*H. The CU*H consumed depends on the compute node specification. For more information, see the Consumption rules.

The unit price for a fixed-specification compute package is CNY 38 per CU*H. Discounts vary by the capacity of the compute package. For the latest pricing, refer to the buy page.

Compute package specifications

  • 5 to 799 CU*H.

  • 800 to 4,999 CU*H.

  • 5,000 to 20,000 CU*H.

Note
  • PolarDB provides a resource package calculator. This calculator helps you estimate the required computing power and recommends a suitable fixed-specification compute package based on your business requirements and usage duration.

  • You receive a 15% discount on packages from 800 to 4,999 CU*H and a 30% discount on packages from 5,000 to 20,000 CU*H.

Deduction rules

The computing units consumed by all nodes in a cluster are deducted hourly.

Example: Consider an Enterprise Edition cluster in the Chinese mainland with one primary node (polar.mysql.x4.large, 4 cores, 16 GB) and two read-only nodes (polar.mysql.x4.large, 4 cores, 16 GB). Each node of this specification consumes 0.04 units per hour. The cluster consumes a total of 0.12 units per hour: one primary node (1 * 0.04 units) plus two read-only nodes (2 * 0.04 units).

Note

The polar.mysql.x4.large specification consumes 0.04 units per hour. See the consumption rule table for how many computing units different node specifications consume.

Consumption rules

Note
  • Each value in the table represents the compute usage of a single node in a subscription compute package.

  • For more information, see How to choose between general-purpose specifications and dedicated specifications.

    • dedicated specification: Uses dedicated computing resources for more stable performance.

    • general-purpose specification: Improves cost-effectiveness by sharing idle computing resources among clusters.

Enterprise edition

Cluster edition

Series

Specification

Chinese mainland

Hong Kong and other regions

Hourly compute units

Hourly fee

Hourly compute units

Hourly fee

Dedicated specifications

polar.mysql.x4.medium

2 vCPUs, 8 GB

0.01 units

CNY 0.38

0.016 units

CNY 0.608

polar.mysql.x8.medium

2 vCPUs, 16 GB

0.033 units

CNY 1.254

0.0594 units

CNY 2.2572

polar.mysql.x4.large

4 vCPUs, 16 GB

0.04 units

CNY 1.52

0.064 units

CNY 2.432

polar.mysql.x8.large

4 vCPUs, 32 GB

0.065 units

CNY 2.47

0.117 units

CNY 4.446

polar.mysql.x4.xlarge

8 vCPUs, 32 GB

0.08 units

CNY 3.04

0.128 units

CNY 4.864

polar.mysql.x8.xlarge

8 vCPUs, 64 GB

0.12 units

CNY 4.56

0.192 units

CNY 7.296

polar.mysql.x4.2xlarge

16 vCPUs, 64 GB

0.15 units

CNY 5.7

0.27 units

CNY 10.26

polar.mysql.x8.2xlarge.gpu

16 vCPUs, 125 GB + one GU100

Note

The polar.mysql.x8.2xlarge.gpu specification is primarily for creating AI models and running inference.

0.7533 units

CNY 28.6254

1.205 units

CNY 45.79

polar.mysql.x8.2xlarge

16 vCPUs, 128 GB

0.24 units

CNY 9.12

0.384 units

CNY 14.592

polar.mysql.x4.4xlarge

32 vCPUs, 128 GB

0.3 units

CNY 11.4

0.54 units

CNY 20.52

polar.mysql.x8.4xlarge

32 vCPUs, 256 GB

0.48 units

CNY 18.24

0.768 units

CNY 29.184

polar.mysql.x8.8xlarge

64 vCPUs, 512 GB

1.12 units

CNY 42.56

1.792 units

CNY 68.096

polar.mysql.x8.12xlarge

88 vCPUs, 710 GB

1.32 units

CNY 50.16

2.112 units

CNY 80.256

General-purpose specifications

polar.mysql.g2.medium

2 vCPUs, 4 GB

0.0089 units

CNY 0.3382

0.01424 units

CNY 0.54112

polar.mysql.g4.medium

2 vCPUs, 8 GB

0.010 units

CNY 0.38

0.016 units

CNY 0.608

polar.mysql.g2.large

4 vCPUs, 8 GB

0.017 units

CNY 0.646

0.0306 units

CNY 1.1628

polar.mysql.g4.large

4 vCPUs, 16 GB

0.0304 units

CNY 1.1552

0.05472 units

CNY 2.07936

polar.mysql.g2.xlarge

8 vCPUs, 16 GB

0.042 units

CNY 1.596

0.0756 units

CNY 2.8728

polar.mysql.g8.2xlarge.gpu

8 vCPUs, 30 GB + one GU30

Note

The polar.mysql.g8.2xlarge.gpu specification is primarily for creating AI models and running inference.

0.2167 units

CNY 8.2346

0.34672 units

CNY 13.17536

polar.mysql.g4.xlarge

8 vCPUs, 32 GB

0.0589 units

CNY 2.2382

0.10602 units

CNY 4.02876

polar.mysql.g4.2xlarge

16 vCPUs, 64 GB

0.122 units

CNY 4.636

0.244 units

CNY 9.272

polar.mysql.g6.2xlarge

16 vCPUs, 96 GB

0.152 units

CNY 5.776

0.2736 units

CNY 10.3968

polar.mysql.g8.2xlarge

16 vCPUs, 128 GB

0.195 units

CNY 7.41

0.351 units

CNY 13.338

polar.mysql.g4.4xlarge

32 vCPUs, 128 GB

0.244 units

CNY 9.272

0.488 units

CNY 18.544

Multi-primary cluster (Database/Table)

Series

Node specification code

CPU and memory

Chinese mainland

Hong Kong (China) and international regions

Hourly compute consumption

Hourly fee

Hourly compute consumption

Hourly fee

Dedicated specifications

polar.mysql.mmx4.xlarge

8 cores, 32 GB

0.08 units

CNY 3.04

0.128 units

CNY 4.864

polar.mysql.mmx8.xlarge

8 cores, 64 GB

0.12 units

CNY 4.56

0.192 units

CNY 7.296

polar.mysql.mmx4.2xlarge

16 cores, 64 GB

0.15 units

CNY 5.7

0.27 units

CNY 10.26

polar.mysql.mmx8.2xlarge

16 cores, 128 GB

0.24 units

CNY 9.12

0.384 units

CNY 14.592

polar.mysql.mmx4.4xlarge

32 cores, 128 GB

0.3 units

CNY 11.4

0.54 units

CNY 20.52

polar.mysql.mmx8.4xlarge

32 cores, 256 GB

0.48 units

CNY 18.24

0.768 units

CNY 29.184

polar.mysql.mmx8.8xlarge

64 cores, 512 GB

1.12 units

CNY 42.56

1.792 units

CNY 68.096

polar.mysql.mmx8.12xlarge

88 cores, 710 GB

1.32 units

CNY 50.16

2.112 units

CNY 80.256

General-purpose specifications

polar.mysql.mmg2.xlarge

8 cores, 16 GB

0.042 units

CNY 1.596

0.0756 units

CNY 2.8728

polar.mysql.mmg4.xlarge

8 cores, 32 GB

0.0589 units

CNY 2.2382

0.10602 units

CNY 4.02876

polar.mysql.mmg4.2xlarge

16 cores, 64 GB

0.122 units

CNY 4.636

0.244 units

CNY 9.272

polar.mysql.mmg6.2xlarge

16 cores, 96 GB

0.152 units

CNY 5.776

0.2736 units

CNY 10.3968

polar.mysql.mmg8.2xlarge

16 cores, 128 GB

0.195 units

CNY 7.41

0.351 units

CNY 13.338

polar.mysql.mmg4.4xlarge

32 cores, 128 GB

0.244 units

CNY 9.272

0.488 units

CNY 18.544

X-Engine

Series

Node specification

CPU and memory

Chinese mainland

Regions outside the Chinese mainland

Hourly compute consumption

Price per hour

Hourly compute consumption

Price per hour

Dedicated specifications

polar.mysql.ax4.large

4 vCPUs, 16 GB

0.04 PCU

CNY 1.52

0.064 PCU

CNY 2.432

polar.mysql.ax4.xlarge

8 vCPUs, 32 GB

0.08 PCU

CNY 3.04

0.128 PCU

CNY 4.864

polar.mysql.ax8.xlarge

8 vCPUs, 64 GB

0.12 PCU

CNY 4.56

0.192 PCU

CNY 7.296

polar.mysql.ax8.2xlarge

16 vCPUs, 128 GB

0.24 PCU

CNY 9.12

0.384 PCU

CNY 14.592

polar.mysql.ax8.4xlarge

32 vCPUs, 256 GB

0.48 PCU

CNY 18.24

0.768 PCU

CNY 29.184

polar.mysql.ax8.8xlarge

64 vCPUs, 512 GB

1.12 PCU

CNY 42.56

1.792 PCU

CNY 68.096

polar.mysql.ax8.12xlarge

88 vCPUs, 710 GB

1.32 PCU

CNY 50.16

2.112 PCU

CNY 80.256

General-purpose specifications

polar.mysql.ag4.large

4 vCPUs, 16 GB

0.0304 PCU

CNY 1.1552

0.05472 PCU

CNY 2.07936

polar.mysql.ag2.xlarge

8 vCPUs, 16 GB

0.042 PCU

CNY 1.596

0.0756 PCU

CNY 2.8728

polar.mysql.ag4.xlarge

8 vCPUs, 32 GB

0.0589 PCU

CNY 2.2382

0.10602 PCU

CNY 4.02876

polar.mysql.ag4.2xlarge

16 vCPUs, 64 GB

0.122 PCU

CNY 4.636

0.2196 PCU

CNY 8.3448

polar.mysql.ag4.4xlarge

32 vCPUs, 128 GB

0.244 PCU

CNY 9.272

0.4392 PCU

CNY 16.6896

Standard edition

X86

Instance family

Node type

CPU and memory

Hourly compute consumption

dedicated specifications

polar.mysql.x4.medium.c

2 vCPUs, 8 GB

0.0146 units

polar.mysql.x8.medium.c

2 vCPUs, 16 GB

0.0186 units

polar.mysql.x2.large.c

4 vCPUs, 8 GB

0.023 units

polar.mysql.x4.large.c

4 vCPUs, 16 GB

0.0294 units

polar.mysql.x8.large.c

4 vCPUs, 32 GB

0.0374 units

polar.mysql.x2.xlarge.c

8 vCPUs, 16 GB

0.0462 units

polar.mysql.x4.xlarge.c

8 vCPUs, 32 GB

0.0588 units

polar.mysql.x8.xlarge.c

8 vCPUs, 64 GB

0.0748 units

polar.mysql.x2.2xlarge.c

16 vCPUs, 32 GB

0.0924 units

polar.mysql.x4.2xlarge.c

16 vCPUs, 64 GB

0.1176 units

polar.mysql.x8.2xlarge.c

16 vCPUs, 128 GB

0.1494 units

polar.mysql.x2.4xlarge.c

32 vCPUs, 64 GB

0.1848 units

polar.mysql.x4.4xlarge.c

32 vCPUs, 128 GB

0.2352 units

polar.mysql.x8.4xlarge.c

32 vCPUs, 256 GB

0.299 units

polar.mysql.x4.8xlarge.c

64 vCPUs, 256 GB

0.4704 units

polar.mysql.x8.8xlarge.c

64 vCPUs, 512 GB

0.598 units

general-purpose specifications

polar.mysql.g1.tiny.c

1 vCPU, 1 GB

0.0005 units

polar.mysql.g1.small.c

1 vCPU, 2 GB

0.0007 units

polar.mysql.g2.small.c

2 vCPUs, 4 GB

0.0098 units

polar.mysql.g4.medium.c

2 vCPUs, 8 GB

0.0126 units

polar.mysql.g8.medium.c

2 vCPUs, 16 GB

0.0168 units

polar.mysql.g2.large.c

4 vCPUs, 8 GB

0.0196 units

polar.mysql.g4.large.c

4 vCPUs, 16 GB

0.0252 units

polar.mysql.g8.large.c

4 vCPUs, 32 GB

0.0336 units

polar.mysql.g2.xlarge.c

8 vCPUs, 16 GB

0.0392 units

polar.mysql.g4.xlarge.c

8 vCPUs, 32 GB

0.0504 units

polar.mysql.g8.xlarge.c

8 vCPUs, 64 GB

0.0672 units

polar.mysql.g2.2xlarge.c

16 vCPUs, 32 GB

0.08 units

polar.mysql.g4.2xlarge.c

16 vCPUs, 64 GB

0.1092 units

polar.mysql.g8.2xlarge.c

16 vCPUs, 128 GB

0.1348 units

Yitian ARM

Instance family

Node type

CPU and memory

Hourly compute consumption

dedicated specifications

polar.mysql.x4m.medium.c

2 vCPUs, 8 GB

0.0108 units

polar.mysql.x8m.medium.c

2 vCPUs, 16 GB

0.0146 units

polar.mysql.x2m.large.c

4 vCPUs, 8 GB

0.015 units

polar.mysql.x4m.large.c

4 vCPUs, 16 GB

0.0226 units

polar.mysql.x8m.large.c

4 vCPUs, 32 GB

0.0306 units

polar.mysql.x2m.xlarge.c

8 vCPUs, 16 GB

0.03 units

polar.mysql.x4m.xlarge.c

8 vCPUs, 32 GB

0.0452 units

polar.mysql.x8m.xlarge.c

8 vCPUs, 64 GB

0.0612 units

polar.mysql.x2m.2xlarge.c

16 vCPUs, 32 GB

0.0632 units

polar.mysql.x4m.2xlarge.c

16 vCPUs, 64 GB

0.0946 units

polar.mysql.x8m.2xlarge.c

16 vCPUs, 128 GB

0.1284 units

polar.mysql.x2m.4xlarge.c

32 vCPUs, 64 GB

0.1264 units

polar.mysql.x4m.4xlarge.c

32 vCPUs, 128 GB

0.1892 units

polar.mysql.x8m.4xlarge.c

32 vCPUs, 256 GB

0.2568 units

general-purpose specifications

polar.mysql.g1m.tiny.c

1 vCPU, 1 GB

0.0005 units

polar.mysql.g1m.small.c

1 vCPU, 2 GB

0.0007 units

polar.mysql.g2m.small.c

2 vCPUs, 4 GB

0.0059 units

polar.mysql.g4m.medium.c

2 vCPUs, 8 GB

0.0078 units

polar.mysql.g8m.medium.c

2 vCPUs, 16 GB

0.0106 units

polar.mysql.g2m.large.c

4 vCPUs, 8 GB

0.0108 units

polar.mysql.g4m.large.c

4 vCPUs, 16 GB

0.0162 units

polar.mysql.g8m.large.c

4 vCPUs, 32 GB

0.022 units

polar.mysql.g2m.xlarge.c

8 vCPUs, 16 GB

0.0226 units

polar.mysql.g4m.xlarge.c

8 vCPUs, 32 GB

0.0338 units

polar.mysql.g8m.xlarge.c

8 vCPUs, 64 GB

0.0458 units

polar.mysql.g2m.2xlarge.c

16 vCPUs, 32 GB

0.0452 units

polar.mysql.g4m.2xlarge.c

16 vCPUs, 64 GB

0.0676 units

polar.mysql.g8m.2xlarge.c

16 vCPUs, 128 GB

0.0916 units

Application order

If you purchase multiple fixed-specification compute packages, the fixed-specification compute packages are deducted in ascending order of their expiration time. If their expiration time is the same, the packages are deducted in the order they were purchased. The fixed-specification compute package that was purchased first is deducted first.

Best practices

  • For workloads with high or frequent fluctuations, pair a Compute Plan with the DAS autonomous service. After you purchase a Compute Plan, enable auto scaling for your pay-as-you-go cluster. When the cluster configuration is adjusted, the Compute Plan automatically applies deductions based on the new specification.

  • This example shows how to estimate Compute Plan capacity.

    • Billing plan:

      pay-as-you-go + Compute Plan.

    • Sample PolarDB requirements:

      • The cluster is in a Chinese mainland region.

      • Specification A (two nodes): used for 330 days.

      • The cluster is upgraded to Specification B (two nodes) for 30 days during a sales promotion.

      • A third node of Specification B is added for the same 30-day period.

      Note

      In this example, Specification A is 2 vCPUs, 8 GB and Specification B is 4 vCPUs, 16 GB.

    • Estimated compute consumption (units):

      Estimated capacity = Hourly consumption per node × Hours × Number of nodes.

      • Specification A: 158.4 units

        0.01 units × 24 hours × 330 days × 2 nodes = 158.4 units

      • Specification B: 86.4 units

        0.04 units × 24 hours × 30 days × 3 nodes = 86.4 units

      Note

      0.01 units and 0.04 units are the hourly compute consumption for Specification A and Specification B, respectively. For a list of consumption rates for all node specifications, see the Consumption Rules Table.

    In this example, the total required capacity for the Fixed Compute Unit (FCU) is at least 244.8 CU*H (158.4 CU*H + 86.4 CU*H). To account for potential business fluctuations, we recommend adding a buffer of about 5%. Therefore, an FCU with a capacity of 260 CU*H can meet the requirements. Because the capacity of the purchased FCU is less than 800 CU*H, the price is CNY 34.2 per CU*H, and the total cost for the FCU is CNY 8,892 (260 CU*H × CNY 34.2/CU*H).

Related operations

Purchase fixed-spec computing plan

Go to the PolarDB purchase page to purchase a fixed-spec computing plan. On the purchase page, set Resource Plan Type to Computing Plan and Applicable Database Type to PolarDB. For Computing Plan Specification, select a range, such as 5 to 800 (CU·h), 800 to 5,000 (CU·h), or 5,000 to 20,000 (CU·h), and then use the slider to set the Computing Plan Capacity (for example, 100 CU·h). After you set the Quantity, the Configuration Summary section on the right summarizes your selections.

Parameter

Description

Effective Time

  • Take Effect Immediately: The computing plan takes effect and starts applying deductions immediately after purchase.

  • Take effect at a specified time (hourly): The resource takes effect at the specified time, and its subscription duration also begins at that time.

Subscription Duration

The validity period of the fixed-spec computing plan.

Note

If you select Use within 1 year. Forfeited upon expiration., the purchased fixed-spec compute package is valid for one year. After it expires, the remaining capacity will be forfeited.

View fixed-spec compute package usage

You can go to the PolarDB console > Resource Plans page. On the Fixed-spec Compute Packages tab, you can view your purchased fixed-spec compute packages and the Remaining/Total for each.

The resource plan list displays information such as Resource Plan ID, Specifications, Computing Plan Status, Resource Type, Remaining/Total, Purchase Time, and Effective Time. The Actions column contains an Unsubscribe option.

Click Usage Details. You are redirected to the Costs > Account > Resource Plan page to view the usage details of the current fixed-spec compute package. The main parameters are described as follows:

  • Deducted Resource Instance ID: The ID of the deducted resource instance. The format is pc-xxxxx (cluster ID);pi-xxxxx (compute node ID).

  • Deduction Factor: The hourly CU consumption of a compute node.

  • Original Usage of Resource Instance: Fixed at 1 CU.

  • Deducted Amount: The amount deducted from the resource plan, which is calculated using the following formula: Original Usage of Resource Instance × Deduction Factor.

  • Balance Before Deduction: The remaining capacity of the resource plan before the deduction.

  • Balance After Deduction: The remaining capacity of the resource plan after the deduction.

Note
  • A fixed-spec computing plan deducts the hourly consumption of all nodes in a cluster. For detailed deduction rules, see Deduction rules.

  • You can choose to have a Compute Plan take effect immediately after purchase. However, the deduction information is typically displayed after a 6-hour delay. We recommend that you check again after some time.

Canceling a fixed-spec compute package

  1. Go to the PolarDB console > Resource Plan page. On the Fixed-specification compute package tab, find the target Fixed-specification compute package, and click Unsubscribe in the Actions column.

  2. After you click Unsubscribe, you are redirected to the Costs > Orders > Resource Unsubscription page. Under the Unsubscribe Resources and Resource Plans options, click Search, find the target storage plan, and click Unsubscribe Resource.

    For Type, select Partial Unsubscription. For Product Name, select PolarDB Compute Plan.

Note
  • You cannot unsubscribe from a fixed-spec computing plan if it has expired or has no remaining capacity.

  • For information about where your refund is sent, see refund destination.

FAQ

Purchase and use

How to use fixed-specification compute package?

For a pay-as-you-go cluster, do I have to purchase a fixed-specification compute package?

No. You can decide whether to purchase a fixed-specification compute plan based on your business needs. After purchase, the plan automatically covers the fixed-specification compute node fees for your pay-as-you-go cluster.

Fixed-spec compute packages Are coupons supported?

You can check the scope of a coupon to determine whether it can be used for a Fixed-specification compute package. If you confirm that your coupon is applicable to a Fixed-specification compute package but you cannot use it to cover the fee when purchasing a Fixed-specification compute package, please contact us.

Compute Plan: Can it increase the compute capacity of a cluster?

No. A fixed-specification compute plan is a billing feature used to cover the fixed-specification compute node fees for pay-as-you-go clusters. The computing power of a cluster depends on the compute node specifications you purchase. To increase computing power, upgrade your cluster configuration. For more information, see Change configuration.

Is the Pay-as-you-go + Compute Plan billing method more cost-effective?

The most cost-effective billing model depends on your business scenario. For more information, see Combine with resource plans.

Estimating price and specifications

You can use the Pricing Calculator and the Resource Plan Calculator to get an estimate.

Supported clusters

Can all PolarDB clusters use Compute Plans?

No. A fixed-specification compute plan can only be used for PolarDB clusters with a compute billing method of pay-as-you-go (also known as postpaid or pay-by-the-hour).

If a subscription cluster is temporarily upgraded or if read-only nodes are added to a subscription cluster, can the computing resources consumed by the nodes with new specifications or the newly added read-only nodes be deducted from a Fixed Compute Unit (FCU)?

No. You must first convert the subscription cluster to a pay-as-you-go cluster to use a fixed-specification compute plan. For more information, see Convert the compute billing method.

Can a Compute Plan be used for a PolarDB cluster that was created before the purchase of the Compute Plan?

Yes.

Compute Plan Can it be shared by multiple clusters, or by read-only nodes within the same cluster?

Yes.

Can I specify a cluster to use a fixed-specification compute package for deduction?

You cannot assign a fixed-specification compute package to a specific cluster. Instead, after you purchase a fixed-specification compute package, it is automatically used to offset the fees for the fixed-specification resources of compute nodes in all pay-as-you-go clusters under your account. If the remaining computing resources in the fixed-specification compute package are insufficient to cover the fees, the overage is charged on a pay-as-you-go basis (for information about pay-as-you-go pricing, see Compute node billing rules), or you can purchase another fixed-specification compute package.

Eligible resources

Can a fixed-spec compute package offset pay-as-you-go cluster fees?

No. When you use a PolarDB cluster, you are charged for compute nodes, storage space, backup storage (beyond the free quota), SQL Explorer (optional), and cold data archiving (optional). Typically, compute node fees account for approximately 65% of the total fees for the cluster.

After you purchase a fixed-specification compute package, the fixed-specification resources of compute nodes in a pay-as-you-go cluster are no longer billed on an hourly basis. Instead, fees are deducted from the fixed-specification compute package on an hourly basis based on your compute consumption (CU*H, also known as units). However, other fees cannot be deducted from the fixed-specification compute package.

If the cluster configuration is adjusted, for example, the cluster is automatically upgraded after auto scaling is enabled or read-only nodes are added after read/write splitting is enabled, can the Fixed-Specification Compute Package automatically deduct compute node fees based on the new cluster specifications or number of nodes?

Yes. When a cluster configuration is adjusted, the fixed-spec compute package automatically deducts the fees for fixed-specification resources of compute nodes from all pay-as-you-go clusters under your account based on the current specifications. For more information about fixed-spec compute package deductions, see View fixed-spec compute package usage.

Fixed Compute Unit (FCU)Are fee deductions related to service network traffic?

The fees offset by a fixed-specification compute package are independent of network traffic. A fixed-specification compute package is used only to offset the resource fees for the fixed specifications of compute nodes in a PolarDB cluster. The offset amount depends on the compute node specifications and usage duration, and is independent of your network traffic. For more information about the deductions of a fixed-specification compute package, see View the usage of fixed-specification compute packages.

Deduction order

PolarDB clusters support three types of resource plans: fixed-specification compute plans, Serverless compute plans, and storage plans. You can purchase and stack multiple plans of each type.

  • Fixed-specification compute plans cover the fees for fixed-specification compute node resources of pay-as-you-go clusters in all regions under your account and are shared across these clusters.

  • A Serverless compute plan can be used to deduct the dynamic resource fees for compute nodes in Serverless clusters and the Serverless feature of fixed-specification clusters in all regions under your account (shared by multiple clusters).

  • Storage plans are available in two types: for Chinese mainland and for regions in China (Hong Kong) and outside the Chinese mainland. Each type of plan is shared by all PolarDB clusters within its specified regions.

If you have multiple plans of the same type, the following rules determine the deduction order and how excess usage is billed:

  • Plans are applied based on their expiration date; the one expiring soonest is used first. If multiple plans have the same expiration date, they are applied in the order they were purchased.

  • Once the capacity of all plans of the same type is exhausted, any remaining usage is automatically billed at the standard pay-as-you-go rate.

Upgrades and renewals

Can I upgrade a fixed-spec compute package?

No. If a fixed-specification compute plan has insufficient capacity, you can purchase another one to add capacity. When you have multiple fixed-specification compute plans, they are applied in a specific order. For more information, see Deduction order.

Is renewal supported for fixed-spec compute packages?

No. Each fixed-spec compute package has a validity period of 1, 3, or 5 years. Any remaining capacity in the fixed-spec compute package automatically expires after the validity period ends. If a fixed-spec compute package is about to expire or has expired, you can purchase another fixed-spec compute package. For information about the deduction order after you purchase multiple fixed-spec compute packages, see Deduction Order.

Other questions

Why can't I see the deduction details of the fixed-specification compute package in Billing Management?

You can choose to have your fixed-specification compute plan take effect immediately after ordering, but deduction details may be delayed by up to six hours. We recommend that you check again later. For more information, see View fixed-specification compute plan usage.

Compute Plan: How to unsubscribe?

You can unsubscribe from a fixed-specification compute plan in the console. For detailed steps, see Unsubscribe from a fixed-specification compute plan.