What's the magic to make IIS process the local URL Rewrite rules before the WebSphere plugin is invoked?
We've already moved URL Rewrite module and Request Filtering module to the first and second items in the globalModules list in applicationhost.config
Looking at the Failed Request Traces, the GLOBAL URL Rewrite rules (the ones defined at the IIS Node level) execute before the WAS plugin. But the local URL Rewrite rules (the rules defined at the root of a web server) execute AFTER the WAS plugin.
That's not going to work. Filters aren't especially useful when they're invoked AFTER the URL has already been processed :-)
And worse than that, the WAS plugin takes the URL that was passed in to IIS (i.e. the RequestURL), puts that in to a header that gets passed to WebSphere and creates: NewUrl="/sePlugins/iisWASPlugin_http.dll"
So by the time that the URL Rewriter is invoked to process the local rules what it sees is:
RequestURL="/sePlugins/iisWASPlugin_http.dll", Scope="Distributed", Type="Inbound"
IOW, they forget to put the original URL and query string back into "RequestURL" so what the filter sees as its input string is literally: sePlugins/iisWASPlugin_http.dll"