Question

I’m looking through a legacy system and have found that the Dundas charts throws a file not found exception quite often, but not all the time.

The system has multiple servers picking up requests and it has therefore set Dundas to run using a server farm configuration (Recommended by dundas support), as in this example:

<appSettings>
    <add key="ChartHttpHandler" value="Storage=file;Timeout=180;
     Url=http://dundas.com/temp/;Dir=\\dundas\wwwroot\inetpub\website\temp"/>

The chart images cannot be found a lot of the time, and I have a feeling it has to do with the multiple servers.

My charts have the properties: ajaxzoomenabled="true" callbackstatecontent="All"

The servers run IIS6 and our NBL affinity is set to use no affinity:

No Affinity

With No affinity, NLB does not associate clients with a particular
member. Every client request can be load balanced to any member. This
affinity provides the best performance but might disrupt clients with
established sessions, because subsequent requests might be load
balanced to other members where the session information does not
exist.

Any suggestions?

Regards.

Answer 1

This is due to the fact that each server has a different web.config, all pointing to their own storage instead of sharing a single storage point.