Server Load Balancer:Pay-as-you-go

Billing rules

Item	Description
Billing rules	The pay-as-you-go billing method allows you to use resources before you pay for the resources. Bills are generated and fees are deducted after each billing cycle.
Use scenarios	The pay-as-you-go billing method is ideal for the following scenarios: The resource usage fluctuates. The workloads expect temporary traffic spikes.
Billing cycles	Fees are calculated on an hourly basis (UTC+8). When the fees within a billing cycle are generated, a new billing cycle begins. For example, if you create a pay-as-you-go CLB instance at 09:30:00 (UTC+8) and release the instance at 12:30:00 (UTC+8), the usage duration is 4 hours. Note If the total amount of the balance and vouchers in your Alibaba Cloud account is less than the fee that you need to pay, you are notified by text message or email.
Configuration changes	The following figure shows the metering methods and configuration changes of pay-as-you-go CLB instances. Pay-as-you-go CLB instances support the pay-by-LCU and pay-by-specification metering methods. You can switch between the metering methods. For more information, see Change the configuration of a pay-as-you-go instance. Internet data transfer that is billed based on the pay-as-you-go billing method supports the pay-by-bandwidth and pay-by-data-transfer metering methods. CLB allows you to switch between the metering methods. You can change the specification and maximum bandwidth of a pay-by-specification CLB instance. For more information, see Modify the configurations of pay-as-you-go CLB instances.
Effective time of configuration changes	If you change the configuration of a CLB instance but do not change the metering method of Internet data transfer, the change immediately takes effect. If you change the configuration of a CLB instance and also change the metering method of Internet data transfer, the changes take effect at 00:00:00 (UTC+8) on the next day.
Bandwidth limits	Pay-by-data-transfer CLB instances: The maximum bandwidth is not a guaranteed value. It indicates the upper limit of bandwidth and is for reference only. In case of resource contention, the bandwidth allocated to each CLB instance may be lower than the maximum bandwidth value. Pay-by-bandwidth CLB instances: The maximum bandwidth is a guaranteed value. In scenarios where demand outstrips resource supplies, the bandwidth can reach the specified value. For more information, see Bandwidth limits.

Metering methods

Pay-as-you-go CLB instances support the pay-by-LCU and pay-by-specification metering methods. The billable items of a CLB instance vary based on the metering method and network type of the CLB instance, and the metering method of Internet data transfer.

Instance fee

• Description

  You are charged instance fees for CLB instances on an hourly basis. If the usage duration in a billing cycle is less than 1 hour, the usage duration is rounded up to 1 hour. The usage duration refers to the period of time from when a CLB instance is created to when the CLB instance is released.

  Note

  You are not charged instance fees for internal-facing CLB instances.

• Calculation formula

  Instance fee = Instance unit price (USD/hour) × Duration of usage (hours)

• Pricing

  Click to view the unit prices in different regions. The prices in the following table are for reference only. The prices on the buy page shall prevail.

  Region	Instance fee (USD/hour)
  China (Hangzhou), China (Shanghai), China (Qingdao), China (Beijing), China (Zhangjiakou), China (Hohhot), China (Shenzhen), China (Heyuan), and China (Chengdu)	0.003
  China (Hong Kong), Japan (Tokyo), UAE (Dubai), and South Korea (Seoul)	0.009
  US (Silicon Valley) and US (Virginia)	0.005
  Singapore, Malaysia (Kuala Lumpur), Indonesia (Jakarta), UK (London), Germany (Frankfurt), and Thailand (Bangkok)	0.006

• Example

  Alice purchased an Internet-facing CLB instance at 10:00:00 (UTC+8) on January 20, 2022 in the China (Hangzhou) region and released the CLB instance at 12:34:00 (UTC+8) on January 21, 2022. The instance fee is calculated based on the following formula:

  Instance unit price in the China (Hangzhou) region = USD 0.003 per hour
  Usage duration = 27 hours
  Instance fee = USD 0.003 per hour × 27 hours = USD 0.081

Specification fee and LCU fee

Specification fee

You are charged specification fees only for pay-by-specification CLB instances. The following section describes the key metrics of high-performance CLB instances. The performance of a CLB instance varies based on the specification.

• Maximum number of connections

  The maximum number of connections that can be established to a CLB instance. When the number of existing concurrent connections reaches the upper limit, new connection requests are dropped.

• Connections per second (CPS)

  The maximum number of new connections that can be established to a CLB instance per second. When the actual number reaches the upper limit, new connection requests are denied.

• Queries per second (QPS)

  The maximum number of HTTP or HTTPS requests that can be processed per second. This metric is specific to Layer 7 listeners. When the actual number reaches the upper limit, new requests are denied.

Example: Alice purchased an Internet-facing CLB instance of the slb.s2.small specification at 10:00:00 (UTC+8) on January 20, 2022 in the China (Hangzhou) region and released the CLB instance at 12:34:00 (UTC+8) on January 21, 2022. The specification fee is calculated based on the following formula:

Unit price of the slb.s2.small specification in the China (Hangzhou) region = USD 0.05 per hour
Usage duration = 27 hours
Specification fee = USD 0.05 per hour × 27 hours = USD 1.35

LCU fee

A Load Balancer Capacity Unit (LCU) is the smallest unit that is used to measure resources consumed by CLB instances.

Definition

You are charged LCU fees of CLB on an hourly basis. The billing cycle is 1 hour. If the usage duration in a billing cycle is less than 1 hour, the usage duration is rounded up to 1 hour.

LCU fee per hour = LCU unit price (USD per LCU) × Number of LCUs consumed per hour

Number of LCUs per hour = max {Number of LCUs consumed by new connections, Number of LCUs consumed by concurrent connections, Number of LCUs consumed by data transfer, Number of LCUs consumed by rule evaluations}

LCUs are used to measure the performance when CLB processes traffic. The performance metrics of an LCU vary based on the protocol of the CLB listener.

• TCP traffic

  Metric	Description	Unit	LCU coefficient	Calculation
  Number of new connections	The number of new TCP connections processed per second.	Seconds	800	The system collects all CPS values within a billing cycle and then divides the largest CPS value by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated based on the following formula: Number of LCUs = Largest CPS value/LCU coefficient
  Number of concurrent connections (CONNS)	The number of concurrent TCP connections per minute.	Minutes	100,000	The system collects all CONNS values within a billing cycle and then divides the largest CONNS value by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated based on the following formula: Number of LCUs = Largest CONNS value/LCU coefficient
  Amount of data transfer	The amount of data transfer over TCP that is processed by CLB. Unit: GB.	Hours	1 GB	The system divides the total amount of data transfer over TCP within a billing cycle by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated based on the following formula: Number of LCUs = Total amount of data transfer/LCU coefficient

• UDP traffic

  Metric	Description	Unit	LCU coefficient	Calculation
  Number of new connections	The number of new UDP connections processed per second.	Seconds	400	The system collects all CPS values within a billing cycle and then divides the largest CPS value by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated based on the following formula: Number of LCUs = Largest CPS value/LCU coefficient
  Number of CONNS	The number of concurrent UDP connections per minute.	Minutes	50,000	The system collects all CONNS values within a billing cycle and then divides the largest CONNS value by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated based on the following formula: Number of LCUs = Largest CONNS value/LCU coefficient
  Amount of data transfer	The amount of data transfer over UDP that is processed by CLB. Unit: GB.	Hours	1 GB	The system divides the total amount of data transfer over UDP within a billing cycle by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated based on the following formula: Number of LCUs = Total amount of data transfer/LCU coefficient

• HTTP and HTTPS traffic

  Metric	Description	Unit	LCU coefficient	Calculation
  Number of new connections	The number of new HTTP and HTTPS connections processed per second.	Seconds	25	The system collects all CPS values within a billing cycle and then divides the largest CPS value by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated based on the following formula: Number of LCUs = Largest CPS value/LCU coefficient
  Number of CONNS	The number of concurrent HTTP and HTTPS connections per minute.	Minutes	3,000	The system collects all CONNS values within a billing cycle and then divides the largest CONNS value by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated based on the following formula: Number of LCUs = Largest CONNS value/LCU coefficient
  Amount of data transfer	The data transfer over HTTP and HTTPS that is processed by CLB. Unit: GB.	Hours	1 GB	The system divides the total amount of data transfer over HTTP and HTTPS within a billing cycle by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated based on the following formula: Number of LCUs = Total amount of data transfer/LCU coefficient
  Number of rule evaluations	The product of the number of forwarding rules processed by CLB and the number of queries per second (QPS). The first 25 forwarding rules are free of charge. If the number of forwarding rules processed by CLB is greater than 25, the following formula applies: Number of rule evaluations = QPS × (Number of forwarding rules processed by CLB - 25). If the number of forwarding rules is less than 25, the following formula applies: Number of rule evaluations = QPS.	Seconds	1,000	The system collects the number of forwarding rules and all QPS values within a billing cycle and uses the largest QPS value to calculate the number of rule evaluations. Then, the system divides the number of rule evaluations by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated based on the following formula: Number of LCUs = Number of rule evaluations/LCU coefficient

The number of LCUs that are consumed by a CLB listener per hour is equal to the largest number of LCUs consumed for different metrics. The LCU fee of a CLB instance is the sum of the LCU fees for all listeners.

LCU unit prices

After the hourly metrics of a CLB instance are converted into LCUs, the hourly LCU consumption is calculated based on the actual usage. The LCU consumption is accurate to 0.000001 LCU. For example, if you consume 0.1 LCU in an hour, the LCU fee for the hour is calculated based on the following formula: 0.1 × 0.007 = USD 0.0007.

Billing examples

1600÷800=2

100÷25=4

480,000÷100,000=4.8

12,000÷3,000=4

4÷1=4

3.6÷1=3.6

(40-25)×400=6,000

6,000÷1,000=6

LCU fee for the TCP listener = USD 0.007 × 4.8 = USD 0.0336
LCU fee for the HTTP listener = USD 0.007 × 6 = USD 0.042
Hourly LCU fee for the CLB instance = LCU fee for the TCP listener + LCU fee for the HTTP listener = USD 0.0336 + USD 0.042 = USD 0.0756
The average monthly LCU fee for the CLB instance is calculated based on the following formula: USD 0.0756 × 24 × 30 = USD 54.432

Internet data transfer fee

Data transfer fee (charged for pay-by-data-transfer Internet-facing instances)

• Description

  You are charged for outbound data transfer over the Internet. You are not charged for inbound data transfer over the Internet. You are charged and billed for pay-by-data-transfer Internet-facing CLB instances on an hourly basis. If the usage duration is less than 1 hour in a billing cycle, the usage duration is rounded up to 1 hour.

• Calculation formula

  Within a billing cycle:
  Data transfer fee = Unit price of data transfer (USD/GB) × Amount of data transfer (GB)

• Pricing

  Click to view data transfer unit prices. The prices in the following table are for reference only. The prices on the buy page shall prevail.

  Region	Data transfer fee (USD/GB)
  China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), China (Hohhot), China (Shenzhen), and China (Heyuan)	0.125
  China (Qingdao)	0.113
  China (Hong Kong)	0.156
  US (Silicon Valley) and US (Virginia)	0.078
  Malaysia (Kuala Lumpur)	0.112
  Singapore, Indonesia (Jakarta), and Thailand (Bangkok)	0.117
  Japan (Tokyo)	0.087
  Germany (Frankfurt) and UK (London)	0.070
  UAE (Dubai)	0.447
  South Korea (Seoul)	0.123

• Example

  Alice purchased an Internet-facing pay-by-data-transfer CLB instance at 10:00:00 (UTC+8) on January 20, 2022 in the China (Hangzhou) region and released the CLB instance at 12:34:00 (UTC+8) on January 21, 2022. The outbound data transfer over the Internet is 5 GB.

  Unit price of data transfer in the China (Hangzhou) region = USD 0.125 per GB
  Outbound data transfer: 5 GB
  Data transfer fee = USD 0.125 per GB × 5 GB = USD 0.625 

Bandwidth fee (charged for pay-by-bandwidth Internet-facing instances)

• Description

  You are charged and billed for pay-by-bandwidth Internet-facing CLB instances on a daily basis. If the usage duration in a billing cycle is less than 1 hour, the usage duration is rounded up to 1 hour. If the usage duration is less than one day, you are charged based on the number of hours that you use a CLB instance. The usage duration is the duration for which a CLB instance uses bandwidth.

  • The bandwidth fee of a pay-by-bandwidth Internet-facing CLB instance is calculated based on a tiered pricing model with 5 Mbit/s as the standard bandwidth value.

  • If you modified the maximum bandwidth of a CLB instance within a billing cycle, you are charged based on the highest value on that day.

  Note

  For pay-by-bandwidth CLB instances, the maximum inbound bandwidth is the same as the maximum outbound bandwidth.

• Calculation formula

  For a CLB instance whose maximum bandwidth is from 1 to 5 Mbit/s, the bandwidth fee is calculated by using the following formula: Bandwidth fee = Maximum bandwidth × Bandwidth unit price × Usage duration.
  For a CLB instance whose maximum bandwidth is higher than 5 Mbit/s, the bandwidth fee is calculated by using the following formula: Bandwidth fee = [5 × Unit price of bandwidth from 1 to 5 Mbit/s + (Maximum bandwidth - 5) × Unit price of bandwidth higher than 5 Mbit/s] × Usage duration.

• Pricing

  Click to view bandwidth unit prices. The prices in the following table are for reference only. The prices on the buy page shall prevail.

  Region	Fee for bandwidth between 1 and 5 Mbit/s (USD/hour)	Fee for bandwidth between 1 and 5 Mbit/s (USD/day)	Fee for bandwidth higher than 5 Mbit/s (USD/hour)	Fee for bandwidth higher than 5 Mbit/s (USD/day)
  China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), China (Hohhot), China (Shenzhen), China (Heyuan), and China (Chengdu)	0.006	0.144	0.02	0.48
  China (Qingdao)	0.005	0.12	0.016	0.384
  China (Hong Kong)	0.006	0.144	0.02	0.48
  Singapore, Indonesia (Jakarta), Malaysia (Kuala Lumpur), Germany (Frankfurt), UK (London), Thailand (Bangkok), and South Korea (Seoul)	0.006	0.144	0.02	0.48
  Japan (Tokyo)	0.007	0.168	0.023	0.552
  UAE (Dubai)	0.048	11.52	0.118	2.832
  US (Silicon Valley) and US (Virginia)	0.006	0.144	0.02	0.48

• Example

  Alice purchased an Internet-facing CLB instance whose maximum bandwidth is 2 Mbit/s in the China (Hangzhou) region at 10:00:00 (UTC+8) on January 20, 2022 and changed the maximum bandwidth to 20 Mbit/s at 08:00:00 (UTC+8) on January 21, 2022. Then, Alice released the CLB instance at 12:34:00 (UTC+8) on January 21, 2022. The bandwidth fee is calculated based on the following formula:

  Maximum bandwidth on the day when Alice purchased the CLB instance: 2 Mbit/s
  Maximum bandwidth on the day when Alice modified the maximum bandwidth of the CLB instance: 20 Mbit/s
  Bandwidth fee for the first day: (2 × 0.006) × 14 = USD 0.168
  Bandwidth fee for the next day: [5 × 0.006 + (20 - 5) × 0.02] × 13 = USD 4.29
  Total fee = 0.168 + 4.29 = USD 4.458