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Estimate a Sustained Authentication Rate

What is the sustained authentication rate for the application?

The sustained authentication rate is based on the authentication load. Specifically, when and at what rate the authentications occur. The chance that the authentication 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 authentication rate is the process of identifying a sustained period during which the system is servicing an average amount of authentication requests.

When estimating a sustained authentication rate, we recommend using the daily authentication load to determine:

• The rate at which the authentication 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 authentication requests.
• The approximate number of authentication 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 authentication requests, per second, that SiteMinder must service to maintain the average rate at which users authenticate, which the following represents:

(authentication_load * percentage_of_authentication_requests) / number_of_sustained_hours / 3600 = sustained_authentication_rate

• authentication_load

  Represents the number of daily authentications for the application.

• percentage_of_authentication_requests

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

  Example: If the authentication load is 50,000 logins, and 32,000 logins occur during the sustained period, then the value is 64percent (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 authentication requests, per second, that SiteMinder must service during the period of sustained activity.

Example: Estimate the Sustained Authentication Rate

The company has determined that their application portal has an authentication load of 88,000 logins. 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 9,000 authentications requests occur per hour.
• Approximately 45,000 (9,000 * 5) authentication requests, or 51 percent (45,000 / 88,000) of the daily authentication load, occur during these hours.

(88,000 * 0.51) / 5 / 3600 = 2.49 authentications per second.

The portal application has a sustained authentication rate of 2.49 authentications per second.