Implementation Guide › Capacity Planning › Estimate a Peak Authorization Rate

Estimate a Peak Authorization Rate

What is the peak authentication rate for the application?

The peak authorization rate is based on the sustained authorization rate, specifically, when and at what rate the system is operating at peak levels. Estimating the peak authorization rate is the process of identifying when the system is servicing the highest level of authorization requests.

When estimating the peak authorization rate, we recommend using the metrics that you gathered when determining the sustained authorization rate to determine:

• The hour the system is servicing the highest number of authorization requests
• The approximate number of authorization requests that occur during this 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 peak rate at which users authenticate, which the following represents:

(authorization_load * percentage_of_transactions) / number_of_hours / 3600 = peak_authorization_rate

Note: This rate is based on the single busiest hour. There can be times when the peak authorization rate exceeds the hourly calculation.

• authorization_load

  Represents the number of daily authorizations for the application.

• percentage_of_transactions

  Represents the percentage of transactions that occur when the system is operating at peak levels.

• number_of_hours

  Represents the number of hours in which the system is operating at peak levels.

• peak_authorization_rate

  Represents the peak authorization rate for the application.

Example: Estimate a Peak Authorization Rate

As detailed in Estimate Daily Authorizations, the portal application has an authorization load of 792,000. System activity reports detail that during the single busiest hour of the day, 260,000 authorization requests occur. This number represents approximately 33 percent of the authorization load.

(792,000 * 0.33) / 1 / 3600 = 72.6 authorizations per second

The portal application has a peak authentication rate of 72.6 authorizations per second.