Server Load Balancer:Pay-as-you-go

LCU usage definition

CLB LCU fees are charged hourly, with each billing cycle lasting one hour. If you use an instance for less than one hour within a billing cycle, the usage duration is rounded up to one 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}

A performance capacity unit (LCU) is a performance metric used to measure the performance of CLB when processing traffic. The performance metrics included in a single LCU depend on the protocol of the CLB listener.

• For TCP traffic

  Metric name	Description	Metering time	LCU coefficient	Calculation of LCUs per hour for each metric
  New connections	The number of new TCP connections processed per second.	Second	800	Within a billing cycle, the system records all new TCP connections per second. Then, the system divides the maximum new connections per second by the LCU coefficient to obtain the number of LCUs for new connections in that billing cycle. The formula is as follows: Number of LCUs = Maximum number of new connections ÷ LCU coefficient
  Concurrent connections	The number of concurrent TCP connections per minute.	Minute	100,000	Within a billing cycle, the system records the concurrent TCP connections per minute. Then, the system divides the maximum concurrent connections per minute by the LCU coefficient to obtain the number of LCUs for concurrent connections in that billing cycle. The formula is as follows: Number of LCUs = Maximum Concurrent Connections ÷ LCU coefficient
  Data processing	The volume of data processed by CLB for TCP requests and responses, in GB.	Hour	1 GB	Within a billing cycle, the system records the total volume of data processed for TCP requests and responses. Then, the system divides the total data volume by the LCU coefficient to obtain the number of LCUs for data processing in that billing cycle. The formula is as follows: Number of LCUs = Total processed data amount ÷ LCU coefficient

• For UDP traffic

  Metric name	Description	Metering time	LCU coefficient	Calculation of LCUs per hour for each metric
  New connections	The number of new UDP connections processed per second.	Second	400	Within a billing cycle, the system records all new UDP connections per second. Then, the system divides the maximum new connections per second by the LCU coefficient to obtain the number of LCUs for new connections in that billing cycle. The formula is as follows: Number of LCUs = Maximum New Connections ÷ LCU coefficient
  Concurrent connections	The number of concurrent UDP connections per minute.	Minute	50,000	Within a billing cycle, the system records the concurrent UDP connections per minute. Then, the system divides the maximum concurrent connections per minute by the LCU coefficient to obtain the number of LCUs for concurrent connections in that billing cycle. The formula is as follows: Number of LCUs = Maximum concurrent connections ÷ LCU coefficient
  Data Volume Processed	The volume of data processed by CLB for UDP requests and responses, in GB.	Hour	1 GB	Within a billing cycle, the system records the total volume of data processed for UDP requests and responses. Then, the system divides the total data volume by the LCU coefficient to obtain the number of LCUs for data processing in that billing cycle. The formula is as follows: Number of LCUs = Total amount of data transfer/LCU coefficient

• For HTTP(S) traffic

  Metric name	Description	Metering time	LCU coefficient	Calculation of LCUs per hour for each metric
  New connections	The number of new HTTP(S) connections processed per second.	Second	25	Within a billing cycle, the system records all new HTTP(S) connections per second. Then, the system divides the maximum new connections per second by the LCU coefficient to obtain the number of LCUs for new connections in that billing cycle. The formula is as follows: Number of LCUs = (Maximum New Connections) ÷ (LCU coefficient)
  Concurrent connections	The number of concurrent HTTP(S) connections per minute.	Minute	3,000	Within a billing cycle, the system records the concurrent HTTP(S) connections per minute. Then, the system divides the maximum concurrent connections per minute by the LCU coefficient to obtain the number of LCUs for concurrent connections in that billing cycle. The formula is as follows: Number of LCUs = Maximum concurrent connections ÷ LCU coefficient
  Processed data volume	The volume of data processed by CLB for HTTP(S) requests and responses, in GB.	Hour	1 GB	Within a billing cycle, the system records the total volume of data processed for HTTP(S) requests and responses. Then, the system divides the total data volume by the LCU coefficient to obtain the number of LCUs for data processing in that billing cycle. The formula is as follows: Number of LCUs = total processed data volume / LCU coefficient
  Rule evaluations	The product of the number of forwarding rules processed by CLB and the queries per second (QPS). The first 25 forwarding rules are free of charge. If the number of forwarding rules is greater than 25, Rule evaluations = QPS × (Number of forwarding rules - 25). If the number of forwarding rules is less than 25, Rule evaluations = QPS.		1,000	Within a billing cycle, the system records all forwarding rule counts and all QPS values, and uses the maximum QPS to calculate the number of rule evaluations. The number of rule evaluations is then divided by the LCU coefficient to obtain the number of LCUs for rule evaluations in that billing cycle. The formula is as follows: Number of LCUs = Number of rule evaluations / LCU coefficient

The number of LCUs consumed by each listener in one hour is calculated based on the preceding metrics. You are charged based on the metric that consumes the most LCUs. The total LCU fee for a single CLB instance is the sum of the LCU fees for all its listeners.

LCU unit price

The unit price of an LCU is USD 0.007 per LCU-hour. The actual price is subject to the price on the purchase page.

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

LCU billing example

You created a pay-by-LCU CLB instance in the China (Hangzhou) region at 08:10:00 on June 8, 2022, configured a TCP listener and an HTTP listener for it, and then released the instance at 08:50:00 on June 8, 2022. The following table shows sample data for the maximum new connections, maximum concurrent connections, data processing volume, and maximum rule evaluations for the CLB instance during the period from 08:10:00 to 08:50:00 (one billing cycle).

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

In this example, the metric that consumed the most LCUs for the TCP listener during the hour is concurrent connections (4.8 LCUs). The metric that consumed the most LCUs for the HTTP listener is rule evaluations (6 LCUs).

LCU fee for the TCP listener = USD 0.007 per unit × 4.8 units = USD 0.0336
LCU fee for the HTTP listener = USD 0.007 per unit × 6 units = 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
Based on the preceding consumption, the average monthly LCU fee for the CLB instance is estimated as follows: USD 0.0756 × 24 hour × 30 day = USD 54.432