If you've ever configured a content source, managed property, or scope in SharePoint 2010 or 2007 Search, you'll be happy to know that configuring these same items in FAST Search for SharePoint is actually a similar experience. Many of the configuration screens in Central Administration are quite similar, it's just a matter of finding the right one. When you configured FAST, you probably noticed that you have two Search Service Applications now. Both of these applications are important and understanding what each one does will help you know where to go when you want to configure something.
The first Search Service Application (or SSA), we'll talk about is the FAST Search Connector. Unfortunately, in the FAST world, there is not a lot of consistency in the way service applications are named. Apparently, more people to read my article on naming conventions. :) For what little consistency there is, you might find this named FASTContent, but there is no guarantee. Enough about naming though, let's talk about what this service application does.
The FAST Search Connector Service Application (or Content SSA) is responsible for feeding content into FAST. It's not the only way to feed content, but it's the one you will probably use the most. It's sole purpose is to provide a familiar SharePoint interface for configuring content sources for SharePoint sites, BCS, file shares, and Exchange public folders like you used to use in SharePoint 2007. This SSA is responsible for content acquisition and feeds content directly to the Content Distributor which then passes it to the Document Procssors. You don't have to configure all of your indexing through this service application, but it is typically the recommended way (not to mention the easiest).
When looking at the Content SSA, you will find that it looks similar to a regular Search Service Application. However, if you look closely you will notice it is missing several links such as Metada Properties, Scopes, Authoritative Pages, Federated Locations, etc. Effectively, the only thing you can configure here is items related to crawling.
The FAST Search Query Search Service Application, typically named FAST Query SSA (or something similar), is responsible for querying the search index as the name implies. Your search center uses this service application to perform queries. When you configure it, you provide a number of URLs to services inside FAST which effectively let it talk to the QR Proxy which in turn talks to the QR Server which eventually sends your query and returns you the results you see. There are several components that it ultimately goes through but we'll cover that in a future article. Since this service application handles querying, think of it when you want to make any configuration changes to the query process such as scopes.
After looking at both service applications, you might have noticed that there is some overlap in settings pages. This is for a reason, but it's not clear at first. Both the Search Connector SSA and the Query SSA have a content sources page. Where do you go to configure content sources in FAST? You go to the Search Connector SSA. Note: you'll hear this referred to as the Content SSA a lot. Why do you go here? Because, this is the SSA that handles indexing. You configure your content sources here, just like you would in SharePoint 2007. There really isn't much difference.
"Wait! Why are there content sources on the Query SSA then?" Good question. :) You might have seen it on slides or heard it through someone, but People Search does not go through FAST. It goes through regular SharePoint Server Search. That means you go to the Query SSA to create a content source to index your User Profile store. Just create a content source with the sps3 protocol as I have describe in my People Search article and you are good to go. Now, I always figured you would have to create a regular Search Service Application to make this happen, but somehow this works. I presume through the use of black magic or something like that.
Looking at the Query SSA, you might notice there is a Metadata Properties link in the navigation. However, you do not use this link for configuring managed properties in FAST. This is only for People Search. Look for the FAST Search Administration link. You want to use this link to get to the page that lets you configure managed properties in FAST. Once you are here, you can configure managed properties just like you did in SharePoint 2007. You can also configure property extraction here as well.
I also want to point out the Search Application Topology section. In a regular search service application, you use this to configure partitions, crawl components and mirroring. You can make changes here, but it has no effect on FAST itself. This is solely for configuring the topology of People Search. If you want to make topology changes to FAST, you still have to use a deployment XML file.
To recap, you use the FAST Search Connector (or Content SSA) to configure things involved in the indexing process (i.e.: Content Sources and Crawl Rules). You use the FAST Query SSA to configure things related to querying (i.e.: Metadata Properties and Scopes) as well as People Search. Hopefully, this clears up why the adminsitration pages are in different places It wasn't clear to me at first, so I am hoping this article is useful to others.