Typically, a user will launch ArcGIS Desktop, open a layer and perform zooming and panning activity throughout the usage of the application which is listed below:

1. Launch ArcGIS Desktop
2. Select layer
3. Perform zooming and panning

As we know that LoadRunner is not a functional tool (refer to “Are client activities recorded by Vugen?”), [1] Launch ArcGIS Desktop will not be recorded as it’s a client activity.  Moving on to [2] Select layer, ArcGIS Desktop will (a) open a dialogue to select the server for connection, and after which (b) provide a list of layers (map services) for the user to select.  After selection, the layer will be loaded onto the main frame inside ArcGIS Desktop.

The selection of [2.a] servers and [2.b] layers (map services) are actually making HTTP request to the ArcGIS Server.  Therefore, Web (HTTP/HTML) protocol will be sufficient to record these activities.

Moving on, [3] the user will perform zooming and panning.  In this activity, ArcGIS Desktop is actually retrieving image files from the ArcGIS Servers.  If you have a Web Server before ArcGIS Server, it will be retrieving the image files from there.  Unless the area that you zoomed in/out or panned isn’t in the cache or readily available in the Web Server, a request is sent to the ArcGIS Server to “re-calculate” the area and generate the map image then send it back to the ArcGIS Destop.  As it is a retrieval of image files, it’s actually a HTTP GET request made from ArcGIS Desktop to the ArcGIS Server for the file, which also can be viewed via the browser.

As such, similarly, for [3] Perform Zooming and panning, Web (HTTP/HTML) protocol will be sufficient to record these HTTP activities.

On the scenario modeling, a typical usage will generally select multiple layers and after the selection of layers, the user will proceed to zoom and pan multiple times.  As such, in planning the scenario, it is advisable to have the [2.a] performed once, [2.b] performed to the required layers (e.g. 8 map services of different terrains) and [3] multiple times controlled by pacing.  The duration of the scenario will be dependent on your load testing requirements.

During the load test, in a typical setup, ArcGIS Server will experience higher server utilization due to the processing required in it particularly the processor usage.  This is particularly for [2.a] and [2.b]. Therefore, more resources should be catered for the servers assuming ArcGIS Server roles.  Lastly, do take note if there are any limiting connections on the Web Server (if deployed in the system architecture) as they may restrict the number of connections user can make to the ArcGIS Server.

We will go through the approaches in LoadRunner and briefly touch on the similar options available in SilkPerformer.

[1] Using Web (HTTP/HTML) protocol

The actual approach that was utilized in the load test. Back to the basics, the communication channel used by ArcGIS Desktop (ArcMap) is Web Services over HTTP, that’s SOAP/HTTP. The Web Services include finding the service provided by a ArcGIS Server, calculating and loading of the map. Therefore, normal means of using Web (HTTP/HTML) should suffix. For licensing concerns, Web (HTTP/HTML) protocol is grouped under the Web 2.0 Bundle license.

Further to this, (a) options for capturing the Content-Headers should be enabled and (b) the old recording engine in VUGen should be used. An article will be posted on the sample recording of ArcGIS Desktop (ArcMap) using Web (HTTP/HTML).

[2] Using Web Services protocol

As communcation is using Web Services, the most clear-cut protocol will be Web Services protocol which you can parameterize it with the Wizard. Refer to “Is it possible to load test Web Services without front-end?” . Understanding of the location of the WSDL file and parameters to passed in will be required for this approach. Of course, this requires the SOA Bundle license in order for load execution in Controller.

[3] Using .NET protocol

Using .NET protocol, you will need to know the assemblies and methods used by ArcMap. Therefore, go through the entire list of assemblies and methods that maybe involved in the communication between the client, ArcGIS Desktop (ArcMap) to the server, ArcGIS Server.

[4] Using Visual Studio AddIn

Using Visual Studio AddIn (after the installation of the plugin), you can create the user by calling methods from the ArcGIS SDK. Our evaluation of using ArcGIS SDK was using the C# language and making calls of zooming and panning activities. Unlike the conventional approach of knowing the communication between the client and server, and ignoring the client-activities, in this approach, we focus on the client-activities and ignore the communication used.

Similarly in SilkPerformer (refer to “What’s SilkPerformer” for a review of the product), there are four approaches to record and replay of an activity in ArcGIS Desktop (ArcMap) that are almost the same to LoadRunner with of course a different branding and licensing mechanism.

1] Using Web License

The basic function provided by SilkPerformer with same capabilitis as the Web (HTTP/HTML) protocol in LoadRunner.

[2] Using SOA Edition

Similar to SOA Bundle in LoadRunner, the SilkPerformer SOA Edition allows the reading of WSDL file and generation of the APIs based on the WSDL file.

[3] Using .NET Explorer

Similar to .NET protocol in LoadRunner, SilkPerformer will require the knowledge of the assemblies and methods being used by the user in a normal context. Using the .NET Explorer, SilkPerformer will generate the API based on the selected assemblies and methods.

[4] Using Visual Studio Plugin

Similar to Visual Studio Addin in LoadRunner, an additional plugin provided by SilkPerformer is installed into Visual Studio. And by using the desired langauges (Java, Visual Basic or C#) and the knowledge of ArcGIS SDK, you can create powerful scripts that emulates the activities of the real user.

If you have other approaches in load testing the application, please let us know and we can share it out with everyone here. Our understanding that there are other alternatives such as EggPlant Load Tester and using of RDP (Remote Desktop Protocol in LoadRunner 9.0 onwards) to load test ArcGIS.