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Frequently-Asked Questions about the PI Service

Can I install multiple instances of the PI service on my webserver?

Yes, you can. You might want to do this to isolate critical traffic from non-critical traffic, or to provide a manual failover mechanism during updates

However, simply re-running the setup.exe program won't work - it will ask you whether you intend to remove or repair the PI service. Instead, you must make a copy of the PIService directory and all its contents, and then configure the newly-created folder as a web application.

Making a copy of the PIService directory and its contents is easy. From Windows Explorer, click on the PIService folder (typically c:\Inetpub\wwwroot\PIService for a default installation) to select it, hit

<ctrl>-C, -Vand rename the folder from "Copy of PIService" to something more appropriate

However, to get it to run, we have to tell the webserver that this new folder is an application, not just a collection of files. Configuring the new folder as an application involves just a few more steps. We must manually replicate what the installation program did for us originally. Let's assume you created a copy of the PIService folder and called it PIService_XL.

Open Internet Services Manager (Control Panel | Administrative Tools | Internet Services Manager) and find PIService_XL under Default Web Site. It will be shown with a yellow folder icon, as it is not a standalone web application yet. Right-click and choose Properties to bring up the properties dialog.

Hit the "Create" button to create it as a web application. Change its Execute Permissions to "Scripts and Executables". Set the "Application Protection" to "High (Isolated)". Hit Apply to commit these changes.

Hit the "Configuration" button to bring up the application configuration dialog. Hit the Add button to add a new application mapping.

In the "Add/Edit Application Extenstion Mapping" dialog, use the Browse button to set the Executable field to the "PIServiceIsapi.dll" in your PIService_XL folder. (Make sure you use the one in your new PIService_XL folder, not the one in the original PIService folder!) Set the extension to .srf (yes, you must include the dot). Limit the allowable verbs to GET,HEAD,POST,DEBUG. Clear the Script Engine and Check that File Exists checkboxes. Hit OK to add the .srf mapping.

Repeat the previous step to add a mapping for .dll files. (A handy tip here is to copy and paste the executable that you just configured for the .srf mapping. Both .srf and .dll extensions must be handled by the same PIServiceIsapi.dll.

(Optional, but convenient): Under the "Documents" tab, ensure that the checkbox "Enable Default Document" is checked, and add "PIService.dll" as a default document. You may remove any other default documents you may find there. This allows you to point your browser at http://your_webserver/PIService_XL and save a whole 13 characters when you call up the status console.