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
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 -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
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.