This article provides billing information for Serverless Flink hybrid elastic resource pools, including billing methods, subscription durations, billing cycles, and billable items.

Billing Methods #

You can create Flink resource pools with the hybrid elastic billing method using general resources. Hybrid elasticity includes a fixed part and an elastic part:

• Fixed part: This part requires prepayment. Refer to Annual and Monthly Subscription for the billing model. It is suitable for regular, fixed resource usage and is more cost-effective than pay-as-you-go.
• Elastic part: This part is post-paid. Refer to Pay-As-You-Go for the billing model. It is suitable for handling sudden or temporary resource spikes and offers more flexibility than a monthly subscription.

Subscription Duration #

When creating a hybrid elastic resource pool, you can choose from multiple subscription durations based on your business needs.

• Monthly subscription: you can purchase a subscription for 1 to 11 months.
• Annual subscription: you can purchase a subscription for 1 to 3 years.

Billing cycle #

The billing cycle for a hybrid elastic resource pool is based on your purchased subscription duration (in UTC+8). A billing cycle starts when the resource is created (down to the second) and ends at 23:59:59 on the expiration date.
For example, if you create a resource pool with a 1-month subscription at 14:00:00 on August 4, 2023, the billing cycle is from 14:00:00 on August 4, 2023 to 23:59:59 on September 4, 2023.

Billable items #

The basic unit of computing resources for Serverless Flink is the Compute Unit (CU), where 1 CU = 1 CPU core + 4 GiB of memory.
Currently, the billable items for a hybrid elastic resource pool are as follows:

Pricing for the fixed portion:

The flexible part is billed hourly. The number of CUs is calculated using the formula MAX(CPU, Memory Usage/4 GB):

Let's consider a common hybrid elastic scenario. Assume a customer purchases a 100C/400GB fixed part and uses an additional 100C/400GB. Depending on the usage scenario, see the billing reference below:

Unsubscription and Refunds #

In a hybrid elastic scenario, deleting a resource pool is equivalent to unsubscribing. The refund for the fixed part will be credited to your account balance. Charges for the flexible part will not be refunded.
When you no longer need a resource pool, you can delete it at any time. Click the Delete button next to the resource pool and confirm the action to unsubscribe.
Refund Amount = Actual Amount Paid for the Fixed Part - Monthly Unit Price of the Fixed Part at Purchase × [Days Used ÷ (365 ÷ 12)] × Applicable Discount

Expiration Policy #

Hybrid elastic resource pools combine fixed (pre-paid) and flexible (post-paid) billing methods. To ensure fair and stable resource usage, the platform automatically manages resources according to the following policies when a resource pool expires or an account has an outstanding balance, prioritizing the fixed part. Pay attention to your billing cycle and renew on time to avoid task interruptions.

Non-renewal of expired fixed resources #

• Policy: If fixed resources expire and are not renewed, the system reclaims the entire resource pool and automatically evicts all tasks (including fixed and elastic parts).
• Impact: The resource pool is completely released, and all tasks stop running.

Outstanding balance for elastic resources #

When an outstanding balance on your account prevents payment of post-paid bills, the platform disables the use of elastic resources and prioritizes the normal operation of fixed resources. This is handled in two specific scenarios:

• Scenario 1: No elastic resources are in use
  • The resource pool's limit is automatically adjusted to the fixed portion, allowing only fixed resources to run.
  • Requests for elastic resources are prohibited, but tasks using fixed resources are unaffected.
• Scenario 2: Elastic resources are in use (e.g., 105 CUs are in use while your fixed resource limit is 100 CUs).
  • The system will gradually stop tasks to reduce resource usage to the fixed resource limit (e.g., 100 CUs).
  • The resource pool limit is adjusted to match the fixed resource limit.
  • Task shutdown priority (applied in the following order):
    1. Priority: Tasks are stopped from lowest to highest priority.
    2. CU size: If priorities are the same, tasks with the largest CU usage are stopped first, proceeding in descending order until all elastic resources are released.
    3. Runtime: If priority and CU size are the same, the task with the shortest runtime is stopped first.

Regularly check your resource pool's billing status to ensure timely renewals for fixed resources and a sufficient account balance for elastic resources. You can renew your resources in the following ways:

• You can enable the auto-renewal feature for your resource pool. After enabling auto-renewal, the system will automatically renew your resource pool 7 days before it expires for the purchased duration.
• You can also renew manually before the resource pool expires.

For renewal instructions, see Resource Pool Renewal.