What’s SilkPerformer?

SilkPerformer 2008 is a load testing tool from Borland, originally from Segue. For a start, SilkPerformer are both performance testing tools and bears similarities with LoadRunner such as having a script-generating component (Vugen), a load orchestrating component (Controller) and an analyzing component (Analysis). Therefore, you may like to read about the product LoadRunner in “What’s LoadRunner?” to get a head start of typical performance testing tools before proceeding further on this article. The SilkPerformer suite consists of the Workbench, Silk TrueLog and Silk Performance Explorer. The entire load test implementation is the same where the load generators have to be installed at the machines. For the sales talk, please refer to the official vendor here and its technical publication here for more information. In actual comparison, SilkPerfomer has a close resemblance of Performance Center too. For more information of Performance Center, you may want to refer to “What’s Performance Center?” too.

As both LoadRunner and SilkPerformer offers the same functionality, what SilkPerformer is appealing is it handles load test in a project approach. With this approach, each load test is saved as a project with various settings of profiles and workloads. This is a great feature when you want to track the load test from a customer/project perspective. Furthermore, within a project, for every load test that was executed, a result directory for each run is created. This is useful in tracking the number of runs that were conducted. In this way, there is a structural approach in managing the tests that were conducted (especially useful when you are running multiple load test). As for LoadRunner 9.0, an additional scenario profile setting was introduced in Controller. This feature allows the different configuration of scenario profiles similar to SilkPerformer. Whereas the generation of a results directory in LoadRunner remained the same in the Controller results setting.  SilkPerformer has another great feature, which is resource management of the load generator. By defining a pool of load generators, the load tester is able to have an overview of the resources that is participating in the load test such as if any load generators are being over-worked. This is almost similar to the Resource Pool in Performance Center and is not available in LoadRunner.

During the execution, SilkPerformer allows monitoring of the resources in terms of CPU usage in the Load Generator. This is beneficial when differing problem in resources on the Load Generator or the SUT itself. Furthermore, feature allows capacity planning for load generators. SilkPerformer also allows monitoring on the progress of the vusers in terms of percentage completed by each vuser. This is a great feature that allows the load tester to estimate the duration of the load test and forecast the end time of the load test.

For verifying replay of script, the Silk TrueLog used in SilkPerfomer has better capabilities than Vugen Runtime Viewer. If offers replay of the screens and providing views of the data in and out from the client and server with one single component instead of toggling with runtime viewer and client-server request views.

SilkPerformer allows monitoring similar to LoadRunner. However, as compared with LoadRunner, it has better control and ease-of-use in setting up monitors. On top of this, SilkPerformer requires additional logging for non-default monitors unlike LoadRunner, which automatically logs the data when the counter is been added into the monitor list. Also, SilkPerformer is restricted to a defined set of custom monitors namely JMX, SNMP, Perfmon and Rexec unlike LoadRunner, which provides more monitors.

SilkPerformer utilizes Silk Performance Explorer for analysing. However, it’s capability to merge, manipulate, handle external data is not as flexible and robust as LoadRunner Analysis. The analysing feature is an important component used by the Performance Team to determine problem causes.

SilkPerformer have the similar license mechanism as LoadRunner, which is bounded by a single host. However it features an additional mechanism that allows the option to “check-out” license to the installed application. This is useful in an organization context in managing our performance test in different environments and will be discussed in a later article.