NLB billing rules - 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.

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.
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. In most cases, bills are generated 1 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. You are charged Internet data transfer fees if you use Internet-facing NLB instances. The billing cycle, fee deduction time, and bill generation time are determined by the pay-as-you-go EIPs associated with the NLB instances. For more information, see EIP billing.

Billable items of NLB

NLB charges 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

Starting October 1, 2023, you are charged instance fees for NLB instances.

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. The usage duration refers to the period of time from when an NLB instance is created to when the NLB instance is released.

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

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

Billable item	Instance unit price (USD per hour)
Instance fee	0.02 Note Starting October 1, 2023, you are charged instance fees for NLB instances.

LCU fee

An LCU is the smallest unit used to measure resources consumed by 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 for new connections, Number of LCUs for concurrent connections, Number of LCUs for data transfer}

The performance metrics of a single LCU vary based on the protocols of NLB listeners.

TCP listener

Metric	Description	Unit	LCU coefficient	How the number of LCUs consumed per hour is calculated
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 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.	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 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.	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 by using the following formula: `Number of LCUs = Total amount of data transfer/LCU coefficient`

UDP listener

Metric	Description	Unit	LCU coefficient	How the number of LCUs consumed per hour is calculated
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 by using 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 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.	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 by using the following formula: `Number of LCUs = Total amount of data transfer/LCU coefficient`

TCP/SSL listener

Metric	Description	Unit	LCU coefficient	How the number of LCUs consumed per hour is calculated
Number of new connections	The number of new SSL/TCP connections processed per second.	Seconds	50	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 CONNS	The number of concurrent SSL/TCP 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 by using the following formula: `Number of LCUs = Largest CONNS value/LCU coefficient`
Data transfer	The data transfer over TCP/SSL processed by NLB. Unit: GB.	Hours	1 GB	The system divides the total amount of data transfer that uses SSL 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`

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 listeners.

LCU unit price

After the hourly metrics of an NLB instance are converted into LCUs, the hourly LCU consumption is calculated based on the actual usage. The LCU consumption is accurate to 0.000001 LCUs. For example, if you consume 0.1 LCUs in an hour, the LCU fee for the hour is calculated based on the following formula: 0.1 × 0.005 = USD 0.0005.

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

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

LCU billing examples

Alice created a pay-by-LCU NLB instance in the China (Hangzhou) region at 08:10:00 (UTC+8) on November 2, 2022, and configured TCP and UDP listeners for the NLB instance. Alice released the NLB instance at 08:50:00 (UTC+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 per second	The largest CPS value within the hour is 4,000. The number of LCUs is calculated by using the following formula: `4,000/800 = 5.0`	The largest CPS value within the hour is 2,000. The number of LCUs is calculated by using the following formula: `2,000/400 = 5.0`
CONNS per minute	The largest CONNS value within the hour is 720,000. The number of LCUs is calculated by using the following formula: `720,000/100,000 = 7.2`	The largest CONNS value within the hour is 420,000. The number of LCUs is calculated by using the following formula: `420,000/50,000 = 8.4`
Data transfer per hour	The data transfer over TCP processed by NLB within the hour is 10 GB. The number of LCUs is calculated by using the following formula: `10/1 = 10.0`	The data transfer over UDP processed by NLB within the hour is 8 GB. The number of LCUs is calculated by using the following formula: `8/1 = 8.0`

In this example, the metric for which the TCP listener consumes the largest number of LCUs is data transfer (10.0 LCUs), and the metric for which the UDP listener consumes the largest number of LCUs is the number of concurrent connections (8.4 LCUs).

LCU fee per hour for the TCP listener = USD 0.005 × 10.0 = USD 0.05
LCU fee per hour for the UDP listener = USD 0.005 × 8.4 = USD 0.042
LCU fee for the NLB instance per hour = LCU fee for the TCP listener per hour + LCU fee for the UDP listener per hour = USD 0.05 + USD 0.042 = USD 0.092

Estimate LCU consumption

You can use the NLB LCU Calculator to estimate the number of LCUs consumed by your NLB service.

Internet data transfer fee

You are not charged 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. NLB charges instance fees and bandwidth or data transfer fees for the EIPs. For more information, see Pay-as-you-go.