NLB billable items - Server Load Balancer - Alibaba Cloud Documentation Center

Network Load Balancer (NLB) supports the pay-as-you-go billing method. This topic describes the billable items and billing rules of NLB.

Overview


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.
Billing cycles and bill generation time	NLB instances and Load Balancer Capacity Units (LCUs) are billed on an hourly basis. You are charged based on resource usage. Bills are generally generated within the hour after a billing cycle ends. The time when bills are generated is determined by the system. Internet-facing NLB instances use elastic IP addresses (EIPs) to provide services over the Internet. If you use an Internet-facing NLB instance, you are charged for the data transmitted over the Internet. The billing cycle, fee deduction time, and bill generation time are determined by the pay-as-you-go EIP. For more information, see EIP billing.

Billable items of NLB

The bills for an NLB instance consist of three parts: instance fees, LCU fees, and Internet data transfer fees.


Network type	Instance fee	LCU fee	Internet data transfer fee
Internet-facing	Charged	Charged	Charged
Internal-facing	Charged	Charged	Not charged

Note You are not charged NLB instance fees for a limited period of time.

Instance fee

You are charged NLB instance fees 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. Billing begins when the instance is created and ends when the instance is released.

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

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


Billable item	Instance unit price (USD/hour)
Instance fee	0.02 Note You are not charged NLB instance fees for a limited period of time.

LCU fee

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

LCU usage calculation

NLB charges LCU fees 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/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}

The performance metrics of a single LCU vary with the protocol of NLB listeners.

Transmission Control Protocol (TCP) listeners


Metric	Description	Time unit	LCU coefficient	How the number of LCUs per hour is calculated
Number of new connections (CPS)	The number of new connections processed per second.	Second	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 by using the following formula: `Number of LCUs = Largest 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 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 = Largest CONNS value/LCU coefficient`
Data transfer	The data transfer over TCP processed by NLB. 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`

User Datagram Protocol (UDP) listeners


Metric	Description	Time unit	LCU coefficient	How the number of LCUs per hour is calculated
CPS	The number of new UDP connections processed per second.	Second	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 by using the following formula: `Number of LCUs = Largest 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 = Largest CONNS value/LCU coefficient`
Data transfer	The data transfer over UDP processed by NLB. 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`

Secure Sockets Layer (SSL) listeners


Metric	Description	Time unit	LCU coefficient	How the number of LCUs per hour is calculated
Number of new connections	The number of new SSL connections processed per second.	Second	50	The system collects the values of the number of new SSL connections processed per second within a billing cycle and then divides the largest 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 = Largest CPS value/LCU coefficient`
Number of concurrent connections	The number of concurrent SSL connections per minute.	Minute	3,000	The system collects the values of the number of concurrent SSL connections per minute within a billing cycle and then divides the largest 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 = Largest CONNS value/LCU coefficient`
Data transfer	The data transfer that over SSL processed by NLB. Unit: GB.	Hour	1 GB	The system divides the total amount of data transfer over SSL 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`

The number of LCUs that are consumed by an NLB listener per hour is calculated based on the dominant metric. The LCU fee for an NLB instance is the sum of the LCU fees of each listener.

LCU unit price

The number of LCUs consumed each hour is rounded up to the nearest integer.

Note By default, NLB rounds up the hourly LCU consumption to 1 LCU if the value is less than 1 and rounds up the hourly LCU consumption to the nearest integer if the value is not an integer. For example, if you consume 0.3 LCUs in an hour, the consumption is rounded up to 1 LCU. The LCU fee for the hour is USD 0.005.

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


Billable item	LCU unit price (USD/hour)
LCU	0.005

LCU billing example

You created a pay-by-LCU NLB instance in the China (Hangzhou) region at 08:10:00 (UCT+8) on November 2, 2022, and configured TCP and UDP listeners for the NLB instance. You released the NLB instance at 08:50:00 (UCT+8) on November 2, 2022. The following table describes the largest CPS value, the largest CONNS value, and the total amount of data transfer of the NLB instance from 08:10:00 (UTC+8) to 08:50:00 (UTC+8).


Metric	TCP	UDP
CPS (second)	The largest CPS value within the hour is 4,000. The number of LCUs that are consumed is: `4,000÷800=5`	The largest CPS value within the hour is 2,000. The number of LCUs that are consumed is: `2,000÷400=5`
CONNS (minute)	The largest CONNS value within the hour is 720,000. The number of LCUs that are consumed is: `720,000÷100,000=7.2`	The largest CONNS value within the hour is 420,000. The number of LCUs that are consumed is: `420,000÷50,000=8.4`
Data transfer (hour)	The data transfer over TCP processed by NLB within the hour is 10 GB. The number of LCUs that are consumed is: `10÷1=10`	The data transfer over UDP processed by NLB within the hour is 8 GB. The number of LCUs that are consumed is: `8÷1=8`

The number of LCUs consumed each hour is rounded up to the nearest integer.

In this example, the metric in which a TCP listener uses the most LCUs is data transfer and 10 LCUs are used. The metric in which a UDP listener uses the most LCUs is the number of concurrent connections and 9 LCUs are used.

LCU fee per hour for TCP listeners = 0.005 USD × 10 = 0.05 USD
LCU fee per hour for UDP listeners = 0.005 USD × 9 = 0.045 USD
LCU fee per hour for the NLB instance = LCU fee per hour for a TCP listener + LCU fee per hour for a UDP listener = 0.095 USD

Internet data transfer fee

You are not charged for Internet data transfer fees if you use internal-facing NLB instances. You are charged Internet data transfer fees only if you use Internet-facing NLB instances. Internet-facing NLB instances use EIPs to provide services over the Internet. If you use an Internet-facing NLB instance, you are charged an instance fee and a bandwidth fee or a data transfer fee for the EIP. For more information, see Pay-as-you-go.