Server Load Balancer:Pay-as-you-go

Billing rules

Item	Description
Billing method	The pay-as-you-go billing method allows you to use resources before you pay for them. Bills are generated and fees are deducted after each billing cycle.
Scenarios	The pay-as-you-go billing method is ideal for the following scenarios: Scenarios in which resource usage fluctuates. Your business has short-term requirements on resource usage.
Billing cycle	Fees are calculated on an hourly basis (UTC+8). After fees are calculated, 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 CLB instance at 12:30:00 (UTC+8), you are charged for 4 hours. Note If the total amount of your account balance and the 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 of pay-as-you-go CLB instances and whether you can change the metering method. Pay-as-you-go CLB instances support the pay-by-LCU and pay-by-specification metering methods. You can change the metering method as needed. For more information, see Modify the configurations of pay-as-you-go CLB instances. You are charged Internet data transfer fees based on the pay-by-data-transfer or pay-by-bandwidth metering method. CLB allows you to change the metering method as needed. You can change the specification and maximum bandwidth value of a pay-by-specification CLB instance. For more information, see Change the configuration of a pay-as-you-go CLB instance.
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.
Maximum bandwidth	Pay-by-data-transfer CLB instances: The maximum bandwidth is used for reference only. It indicates the upper limit of the bandwidth. In case of resource contention, the bandwidth allocated to each CLB instance may be lower than its maximum bandwidth value. Pay-by-bandwidth CLB instances: The maximum bandwidth is guaranteed even when resource contention occurs. For more information, see Bandwidth limits.

Specification fee and LCU fee

Specification fee

You are charged specification fees only for pay-by-specification CLB instances. The following section describes the 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: You 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 by using 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 used to measure resources consumed by CLB instances.

LCU usage

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

Number of LCUs consumed per hour = Max {Number of LCUs based on new connections per hour, Number of LCUs based on concurrent connections per hour, Number of LCUs based on data transfer per hour, Number of LCUs based on rule evaluations per hour}

An LCU measures the dimensions on which CLB processes traffic. The performance metrics of a single LCU vary based on the protocol of CLB listeners.

• TCP traffic

  Metric	Description	Unit	LCU coefficient	Calculation
  Number of new connections (CPS)	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 highest CPS value by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated by using the following formula: Number of LCUs = Highest CPS value/LCU coefficient
  Number of concurrent connections (CONNS)	The number of concurrent TCP connections per minute.	Minute	100,000	The system collects all CONNS values within a billing cycle and then divides the highest CONNS value by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated by using the following formula: Number of LCUs = Highest CONNS value/LCU coefficient
  Data transfer	The data transfer over TCP processed by CLB. Unit: GB.	Hour	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 by using the following formula: Number of LCUs = Total amount of data transfer/LCU coefficient

• UDP traffic

  Metric	Description	Unit	LCU coefficient	Calculation
  CPS	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 highest CPS value by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated by using the following formula: Number of LCUs = Highest CPS value/LCU coefficient
  CONNS	The number of concurrent UDP connections per minute.	Minute	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 by using the following formula: Number of LCUs = Highest CONNS value/LCU coefficient
  Data transfer	The data transfer over UDP processed by CLB. Unit: GB.	Hour	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 by using 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 highest CPS value by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated by using the following formula: Number of LCUs = Highest CPS value/LCU coefficient
  Number of concurrent connections	The number of concurrent HTTP and HTTPS connections per minute.	Minute	3,000	The system collects all CONNS values within a billing cycle and then divides the highest CONNS value by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated by using the following formula: Number of LCUs = Highest CONNS value/LCU coefficient
  Data transfer	The data transfer over HTTP and HTTPS processed by CLB. Unit: GB.	Hour	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 by using 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). You can use 25 forwarding rules free of charge. If the number of forwarding rules processed by CLB is greater than 25, the following formula is applied: 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 is applied: 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 highest 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 by using 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 highest number of LCUs consumed on different metrics. The LCU fee of a single CLB instance is the sum of the LCU fees of each listener.

LCU unit price

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 × 5 = USD 0.035
LCU fee for the HTTP listener = USD 0.007 × 6 = USD 0.042
LCU fee for the CLB instance = LCU fee for the TCP listener + LCU fee for the HTTP listener = USD 0.035 + USD 0.042 = USD 0.077
The average monthly LCU fee for the CLB instance can be calculated by using the following formula: USD 0.077 × 24 × 30 = USD 55.44

Metering methods

Instance fee

• Billing description

  You are charged instance fees for CLB on an hourly basis. If you use a CLB instance for less than 1 hour in a billing cycle, 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.
• Formula

  Instance fee = Instance unit price (USD/hour) × Usage duration (hours)

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

  Region	Instance unit price (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 (Singapore), Malaysia (Kuala Lumpur), Indonesia (Jakarta), India (Mumbai), UK (London), Germany (Frankfurt), Australia (Sydney), and Thailand (Bangkok)	0.006

• Example
  You 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 by using 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

Internet data transfer fee

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

• Billing 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.

• Formula

  Within one 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 listed in the following table are for reference only. The actual prices on the buy page shall prevail.

  Region	Data transfer unit price (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 (Singapore), Indonesia (Jakarta), India (Mumbai), and Thailand (Bangkok)	0.117
  Japan (Tokyo)	0.087
  Germany (Frankfurt) and UK (London)	0.070
  UAE (Dubai)	0.447
  Australia (Sydney)	0.096
  South Korea (Seoul)	0.123

• Example
  You 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)

• Billing description
  You are charged and billed for pay-by-bandwidth 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. If the usage duration is less than one day, you are charged for the number of hours that you use a CLB instance. The usage duration is the duration when a CLB instance uses bandwidth.

  • The bandwidth fee of an 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 maximum bandwidth on that day.
  Note

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

• 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 listed in the following table are for reference only. The actual prices on the buy page shall prevail.

  Region	Unit price of bandwidth from 1 to 5 Mbit/s (USD/hour)	Unit price of bandwidth from 1 to 5 Mbit/s (USD/day)	Unit price of bandwidth higher than 5 Mbit/s (USD/hour)	Unit price of 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 (Singapore), Indonesia (Jakarta), India (Mumbai), Malaysia (Kuala Lumpur), Germany (Frankfurt), UK (London), Australia (Sydney), 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
  You purchased a 2 Mbit/s Internet-facing CLB instance 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, you released the CLB instance at 12:34:00 (UTC+8) on January 21, 2022. The bandwidth fees are calculated by using the following formulas:

  Maximum bandwidth on the day when you purchased the CLB instance: 2 Mbit/s
  Maximum bandwidth on the day when you modified the maximum bandwidth of 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