Smart Vuser allocation
This topic describes how to use Smart Vuser allocation to dynamically balance the load generated by Vusers among the specified load generators.
About Smart Vuser allocation
Smart Vuser allocation balances the load generated by Vusers, distributing the load evenly among the requested load generators. This ensures an accurate load test.
Smart Vuser allocation is available in manual performance tests in percentage mode. In this type of test, if Smart Vuser allocation is enabled, the Controller allocates Vusers to each load generator based on the CPU usage of the load generators. Smart Vuser allocation can only determine the allocation of each Vuser before the Vuser is loaded. This means that for Smart Vuser allocation to work, the performance test must be set to load Vusers gradually and not all at once.
When a load generator's CPU usage becomes overloaded (greater than 80%), the Controller receives a message and stops loading Vusers on the overloaded load generator. The Controller automatically distributes Vusers among the other load generators taking part in the test. The Controller stop loading Vusers when there are no other available load generators in the test.
You can monitor the status of a machine's CPU usage using the icons in the Load Generators dialog box (see Distribute load generators). When the CPU usage of a load generator becomes problematic, the icon to the left of the load generator name contains a yellow bar. When the machine becomes overloaded, the icon contains a red bar.
Tip: You can monitor a load generator's CPU usage in greater detail using the Controller and Load Generator Resources monitor. For details, see Controller and Load Generators graph.
Smart Vuser allocation works most efficiently in performance tests with a high number of Vusers.
Enable Smart Vuser allocation
This section explains how to enable Smart Vuser allocation to provide better load balancing for your load generators.
Note: Smart Vuser allocation is supported for Windows load generators only.
To enable Smart Vuser allocation:
Make sure you have an environment with multiple hosts.
In a performance test, set the workload type to By Percentage.
Add multiple groups to the test, and multiple Vusers to each group.
Define the Scheduler to start Vusers gradually.
Assign different load generators to the groups.
Enable Smart Vuser allocation:
In the Groups and Workload tab, select Test Options > More > Test Options.
Check the Use Smart Vuser allocation (only in percentage mode) checkbox.
Run the performance test.
If the CPU exceeds 80% on a particular load generator, all Vusers that have not started running are moved to another load generator in the same test that is not overloaded.
If all load generators in the test are overloaded, Vusers that have not started remain in Idle state until one of the load generators meets the requirements.