Windows operating systems do not dedicate all available resources to a single Windows session. For load testing with UI-based
technologies such as browser-driven web or SAPGUI,
Silk Performer allows you to distribute virtual users over several Windows sessions. This allows you to make better use from resources of
powerful hardware. Virtual users that execute Java or .NetFramework code that is not designed to run in multiple instances
can be spread over several Windows sessions.
Unlike with GUI-level testing, where each virtual user creates its own Windows session, this setting allows you to run more
than one virtual user within a session. How many sessions an agent machine can handle depends on its hardware resources, in
particular on the CPU and memory. This setting is available for the following technologies: browser-driven web, Citrix, SAPGUI,
Java Framework.
When you start a load test,
Silk Performer creates multiple Windows sessions, logs in to the sessions using the credentials, and starts virtual users within the sessions.
Note: When you enable this setting, make sure that your agent machines are set up identically. Also, the agent machines must be
equipped with the Remote Desktop Services (RDS) with appropriately set up licensing options. The Windows sessions are opened
locally from within the Remote Desktop Services host. Thus,
per device licenses are better suited, although
per user licenses work as well.
Tip: The number of virtual users you can run on an agent machine can be read from the agent's capabilities. These default capabilities
are calculated based on the CPU and memory. However, a realistic number for your specific environment and conditions can only
be determined if the user types (the script and settings) are taken into account. The
Evaluate Agent VUser Capacity dialog helps you to determine a good maximum number of virtual users for a particular agent and user type. For more information,
read
Evaluating Agent VUser Capacity.