You can modify the configurations and change the billing method of pay-as-you-go Classic Load Balancer (CLB) instances to meet your business requirements.
Starting at 00:00:00 on June 1, 2025 (UTC+8), you can no longer purchase new pay-by-specification CLB instances. You also cannot change the billing method of existing instances from pay-by-LCU to pay-by-specification. For more information, see Discontinuation of pay-by-specification Classic Load Balancer (CLB) instances.
Overview of pay-as-you-go billing methods
The pay-as-you-go billing method includes two instance billing options: pay-by-LCU and pay-by-specification (discontinued). The following table describes the instance billing methods, instance types, and public network billing methods.
Instance billing method | Instance type | Public network billing method |
Pay-as-you-go | Internet-facing | Pay-by-traffic |
private network | Not applicable | |
Pay-by-specification (discontinued) | Internet-facing | Pay-by-traffic |
Pay-by-bandwidth | ||
private network | Not applicable |
Change from pay-by-specification to pay-by-LCU
Changing the billing method of a pay-by-specification instance to pay-by-LCU does not interrupt service. You can make this change as needed.
Rules for configuration modifications
You do not need to specify an instance type for a pay-by-LCU instance. Each instance supports up to 1,000,000 concurrent connections, 100,000 new connections per second, 50,000 queries per second (QPS), and 5 Gbps of peak bandwidth.
NoteIf you use a Super Large I or higher instance, changing the billing method from pay-by-specification to pay-by-LCU may reduce performance. Proceed with caution.
CLB instances of Super Large I or higher are not available by default. For Layer 4 workloads that require a higher number of concurrent connections, use Network Load Balancer (NLB). For Layer 7 workloads that require higher QPS, use Application Load Balancer (ALB).
For more information about NLB, see What is NLB?.
For more information about ALB, see What is ALB?.
Because the billing method changes, billing data in the Billing Center may be delayed by 1 to 2 hours.
Effective time
If you change the billing method from pay-by-specification to pay-by-LCU without changing the public network billing method, the change takes effect immediately. If you also change the public network billing method from pay-by-bandwidth to pay-by-traffic, all changes take effect at 00:00:00 the next day. You cannot perform other configuration modifications before the changes take effect.
Instance type | Before change | After change | Effective time | ||
Internet-facing | Pay-by-specification | Pay-by-bandwidth | Billing based on usage | Pay-by-traffic | Takes effect at 00:00:00 the next day |
Pay-by-specification | Pay-by-traffic | Usage-based billing | Pay-by-traffic | Takes effect immediately | |
Private network | Pay-by-specification | Pay-by-traffic | Pay-as-you-go | Pay-by-traffic | Takes effect immediately |
Impacts on billing
After you change the billing method from pay-by-specification to pay-by-LCU, you do not need to specify an instance type. The system charges LCU fees based on your actual usage. For more information about the definition and pricing of LCUs, see Pay-as-you-go.
Scenarios
The pay-by-LCU billing method is suitable for services with periodic or large workload fluctuations.
Procedure
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Log on to the CLB console.
Select the region where the target instance is deployed.
On the Instance Management page, find the target instance and, in the Actions column, choose
> Upgrade/Downgrade > Upgrade/Downgrade.On the Upgrade/Downgrade page, set Instance Billing Method to Pay-by-LCU.
Read and select the Terms of Service, click Buy Now, and then complete the payment.
You can view the new billing method of the instance on the Instance Details page.
Upgrade or downgrade a pay-by-specification instance
Rule | Description |
Rules for configuration modifications | You can modify the instance type, public network billing method, and bandwidth of a pay-by-specification instance. |
Effective time | When you upgrade or downgrade a pay-by-specification instance, if the public network billing method is not changed, the modification takes effect immediately. If the public network billing method is changed (for example, from pay-by-bandwidth to pay-by-traffic), all modifications take effect at 00:00:00 the next day. Note If you change the instance type and the public network billing method (from pay-by-bandwidth to pay-by-traffic or from pay-by-traffic to pay-by-bandwidth), the changes take effect at 00:00:00 the next day. |
Impacts on billing | After you modify the instance type, public network billing method, or bandwidth, the system charges you based on the new configurations. For more information about billing rules, see Pay-as-you-go. |
Scenarios | If the instance type, bandwidth, or public network billing method of your pay-by-specification instance does not meet or exceeds your business requirements, you can upgrade or downgrade the instance. |
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Log on to the CLB console.
In the top navigation bar, select the region where the target instance is deployed.
On the Instances page, find the target instance and choose
> Change Specification > Change Specification in the Actions column.On the Upgrade/Downgrade page, configure the following parameters.
Configuration
Description
Instance Billing Method
Select an instance billing method. The instance billing methods include Pay-by-specification and Pay-by-LCU.
To upgrade or downgrade a pay-by-specification instance, set this parameter to Pay-by-specification.
Server Load Balancer Specifications
Select an instance type. You can upgrade or downgrade the instance type.
The performance metrics of a CLB instance vary based on the instance specification. For more information, see CLB instances.
SLB Instance
The current instance type is displayed. You cannot modify the instance type.
Public Network Billing Method
Select a public network billing method.
Pay-by-traffic: An Internet-facing instance is billed based on data transfer.
Pay-by-bandwidth: An Internet-facing instance is billed based on bandwidth.
NoteFor an internal-facing instance, only the pay-by-traffic option is displayed. You are not charged for traffic on an internal-facing instance.
Maximum Bandwidth
Select a bandwidth value.
This parameter is displayed only when you set Public Network Billing Method to Pay-by-bandwidth.
Listener Settings
The listener settings are displayed. You must set a peak bandwidth for each listener. The value must be an integer greater than 0. The sum of peak bandwidth values of all listeners cannot exceed the bandwidth of the instance.
This parameter is displayed only when you set Public Network Billing Method to Pay-by-bandwidth.
Read and select the Terms of Service, click Buy Now, and then complete the payment.
You can view the new instance type, public network billing method, or bandwidth on the Instance Details page.
FAQ
What do I need to know when I change a shared-performance instance to a guaranteed-performance instance?
CLB instances are classified into guaranteed-performance instances and shared-performance instances based on their specifications. Shared-performance instances are no longer available for purchase.
After you change a shared-performance instance to a guaranteed-performance instance, you cannot revert it to a shared-performance instance.
Changing a shared-performance instance to a guaranteed-performance instance does not affect your service or change the IP address of the SLB instance. We recommend performing the change during off-peak hours or using Alibaba Cloud DNS (DNS) to distribute traffic across multiple instances before making the change.
References
User guides:
API references:
ModifyLoadBalancerInstanceChargeType: Changes the instance billing method of a pay-as-you-go CLB instance.
ModifyLoadBalancerInstanceSpec: Modifies the specification of an SLB instance.