Implementation Guide › Capacity Planning › How to Estimate a Sustained Authentication Rate › Estimate Daily Authentications

Estimate Daily Authentications

What is the estimated number of daily authentications for the application?

The number of users directly affect daily authentications (authentication load). When users log into the application, SiteMinder authenticates them. Therefore, think of the authentication load of the application as the total logins per day.

Note: When determining the authentication load, we recommend beginning with an evaluation interval of 24 hours. 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.

All users logging into the application each day is unlikely, so estimating total logins begins with determining the percentage of users that log in once a day, which the following represents:

(total_users * percentage_users) * (number_of_logins) = daily_logins

• total_users

  Represents the total number of users with access to the application.

• percentage_users

  Represents the percentage of users who log in the same number of times per day.

• number_of_logins

  Represents the number of times the particular set of users login.

• daily_logins

  Represents the number of logins the particular set of users creates.

Example 1: The company has 100,000 users, 75 percent of which log in once a day.

(100,000 * 0.75) x (1) = 75,000 logins

However, some users logging into the application two or more times a day is more likely.

Example 2: The company has 100,000 users, 5 percent of which log in twice a day and 1 percent of which log in three times a day.

(100,000 * 0.05) x (2) = 10,000 logins

(100,000 * 0.01) x (3) = 3,000 logins

The total logins per day are the sum of each of the login calculations.

Example 3: The company has 100,000 users:

• 75 percent of which log in once a day, creating 75,000 logins.
• Five percent of which log in twice a day, creating 10,000 logins.
• One percent of which log in three times a day, creating 3,000 logins.

The authentication load for the portal application is 88,000 logins.

Note: The percentage of users logging in does not have to equal 100 percent because all users will not log into the application each day.

The following table illustrates each of the previous examples:

The company uses the authentication load to estimate the sustained authentication rate.