Editor's Note: This tip is excerpted from the authors' recently published book, The Hitchhiker's Guide to SQL Server 2000 Reporting Services (Addison-Wesley, 2005). Two sample chapters and a video of this tip's steps are available for download at http://www.sqlreportingservices.net.
By default, the Microsoft IIS server hosted on Windows XP is configured to a maximum of 10 concurrent connections. This limit can be debilitating when developing with SQL Server 2000 Reporting Services on XP because each Web browser connection consumes more than one connection. Once you start to get 403.9 errors, it appears that even when IIS times out and closes those connections (as confirmed by the performance monitor), you can still get strange errors when opening a new connection. However, at this point, these errors are generated by Reporting Services rather than by IIS.
The solution for this problem is to increase the maximum number of connections to 40 by editing the IIS metabase. We used the IIS MetaEdit utility to make the change. Like the registry editor, this tool comes with warnings such as "Beware a professional with a tool." To tune the IIS metabase on your development system, perform the following steps:
We've not had a problem with 403.9 errors since we increased the limit, but if you still are able to lock up IIS in developer scenarios, you might investigate setting the Connection Timeout property to a lower value to decrease the time before IIS detects that a connection is idle and disconnects it. You can set the Connection Timeout property on the Web Site tab of the Default Web Site Properties dialog box, as Figure 2 shows.