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Estimate a Sustained Authorization Rate

What is the sustained authorization rate for the application?

The sustained authorization rate is based on the authorization load, specifically, when and at what rate the authorizations occur. The chance that the authorization load is uniformly spread across your business day is unlikely. Rather, the rate at which requests occur fluctuates, remaining between the lowest and highest (peak) levels for a sustained period. Estimating the sustained authorization rate is the process of identifying a sustained period during which the system is servicing an average amount of authorization requests.

When estimating a sustained authorization rate, we recommend that you use the daily authorization load to determine:

• The rate at which the authorization requests occur throughout your business day.

  Note: We recommend beginning with an evaluation period of 24 hours, broken down into one-hour increments. However, depending on the requirements of your enterprise, you can compare your daily results over a period of weeks or months to gain a better understanding of usage throughout the year.

• The sustained period during which the system is servicing an average number of authorization requests.
• The approximate number of authorization requests that occur during the sustained period.

The following figure is an example of these metrics:

Identifying these metrics helps you to estimate the number of authorization requests, per second, that SiteMinder must service to maintain the average rate at which authorization requests occur, which the following represents:

(authorization_load * percentage_of_authorization_requests) / number_sustained_hours / 3600 = sustained_authorization_rate

• authorization_load

  Represents the number of daily authorizations for the application.

• percentage_of_authorization_requests

  Represents the percentage of authorization requests that occur when the system is operating at sustained levels.

  Example: If the authorization load is 500,000 requests, and 320,000 requests occur during the sustained period, then the value is 64 percent (0.64)

• number_of_sustained_hours

  Represents the number of hours in which the system is operating at the sustained level.

  Note: 3,600 represents the number of seconds in an hour.

• sustained_authentication_rate

  Represents the number of authorization requests, per second, that SiteMinder must service during the period of sustained activity.

Example: Estimate a Sustained Authorization Rate

As detailed in Estimate Daily Authorizations, the portal application has an authorization load of 792,000. The application portal is available to customers 24 hours a day, seven days a week. Using system activity reports to break down a typical day results in the following metrics:

• The system is operating at sustained levels for approximately five hours (9:00 AM - 2:00 PM)
• During sustained levels, approximately 75,000 authorization requests occur per hour.
• Approximately 375,000 (75,000 * 5) authorization requests, or 47 percent (375,000 / 792,000) of the daily authorization load, occur during these hours.

(762,000 * 0.47) / 5 / 3600 = 19.90 authorizations per second

The portal application has a sustained authorization rate of 19.90 authorizations per second.