Usage metrics on the System landing page helps you to stay informed about the performance of your system by comparing the traffic across different requestors and nodes. With this information, you can check how busy your system is and what kind of traffic is processed most often. Analyzing this data can help you identify the patterns and sources of processing demand, which is helpful in performance tuning.

You can use the System landing page to perform several routine checks, including:

• Identifying peak usage times and assessing the effect of load on the performance of your system.
• Checking whether a recent decline in performance was caused by a sudden increase in the number of users that interacted with the application.

Once an hour and at the logoff of each requestor, your system saves requestor performance details as instances of the Log-Usage class. Instances of this class provide historical statistics for the usage of your system across all nodes and all requestor types. Pega Predictive Diagnostic Cloud (PDC) displays this data on the System landing page.

For more information, see System-wide usage and the Log-Usage class.

PDC views the usage metrics separately for each requestor type, and then categorizes the usage information by the following requestor types:

• Web
  Browser requestors that correspond to user interactions with the application, such as clicking a browser button. The charts for this requestor show the average response time for these interactions.
• Service
  External systems requestors that access Pega Platform™ and listeners.
• Background
  Background processing requestors that handle, for example, listeners, services, agents, and daemons.
• Async
  Requestors that resolve queue processors.
• Stateless
  Data for applications based on the Cosmos React UI Framework.

For more information about requestors, see Requestor Type data instances.

You can filter the information by application and specify a time window. Depending on the specified time window, PDC displays the information aggregated by the day or by the hour. To quickly compare the load between specific nodes and applications, you can choose to split the information for each node and display them concurrently in a single chart for each requestor.

For each node and application, you can view charts that provide the following data:

• Average response time
  The average time that the application took to complete an interaction request. Includes the time that a request spent in a queue.
• Interactions
  The number of times that users or processes interacted with the application in the specified time frame.
• Unique users
  The total number of unique users that accessed the application in the specified time frame.

Depending on the specified time window, PDC counts unique users only once per day or once per hour. For example, if the same user visits the system five times in the same day within an hour interval, and PDC aggregates the results by the day, all visits count as one unique user. However, if PDC aggregates the results by the hour, the same user is counted five times, once for each visit.

You can export the data from these charts into a single .csv file with separate sheets for each chart by clicking Export chart data.

At the bottom of the landing page, you can find hourly snapshots of the data from the charts for each application on each node.

The following figure shows the different functionalities of the Usage statistics landing page in PDC: