One of my most popular blog posts was “Analysis Services 2005 protocol - XMLA over TCP/IP”. Previously this information wasn’t available from anywhere else. But things changed today. Microsoft now has engaged in the “Open Specification program”. Citing from the web page:
Microsoft is providing open connections to its high-volume products—Windows Vista (including the .NET Framework), Windows Server 2008, SQL Server 2008, Office 2007, Exchange Server 2007, and Office SharePoint Server 2007—as well as additional information so that software developers, business partners and competitors can better interact with these Microsoft products or invent new solutions for customers.
As a developer, you now have full access to information about protocols, binary file formats, and other specifications for these products that can be used to create solutions.
(Yes, these include Office file format specifications!)
Since Analysis Services is part of SQL Server, the protocols for accessing Analysis Services are listed under “Microsoft SQL Server Protocols”. The most interesting one is
[MS-SSAS9]: SQL Server Analysis Services Protocol Specification
which documents Analysis Services 2005 protocol (and 2008 as well, since protocol didn’t change between these versions).
There is also
[MS-SSAS8]: SQL Server Analysis Services Protocol Specification
which documents Analysis Services 2000 protocol. However, this one would be much harder to go through, since AS2000 had “smart client” architecture, where client code was doing lots of work – MDX parsing, evaluation, caching etc – therefore the protocol between client and server is at much lower level than MDX queries and it is not easy to make sense out of it.