People often ask me, “When Microsoft is going to get into the type of clustering as defined by Oracle’s RAC (Real Application Clusters)?” Generally, I find these are people who believe the technical concepts behind RAC are the way of the future, so naturally conclude that Microsoft will want to follow.
I have a simple answer to the question, “Microsoft doesn’t intend to implement such a technology”. Naturally this is followed by a pause that demands I say why, so I oblige with the simplest explanation I can muster. “Microsoft believes RAC’s promise of scalability is flawed, flawed by bottle necks in the interconnects between cluster nodes.”
Beyond this I don’t go any further, because I don’t think I need to and because I fear I might step wide of the DOJ’s antitrust consent decree that Microsoft had to sign up to.
Taking the later point; compliance with the DOJ’s antitrust consent decree requires Microsoft does not abuse its monopoly position. This means, as a Microsoft employee, I am not allowed to say anything about our competitors that might be deemed combative or demeaning. For instance, I learn I can no longer refer to a company that runs Oracle as an ‘Oracle shop’. So, knowing that I can demonstrate a combative steak, I feel very reluctant about commenting on our competitors products, for fear of contravening the decree.
Taking the former point, I don’t need to tell you what I think about RAC because there’s so much out there that’s already been said. All I need to do is point to it. In the first instance, I’m going to point you to a document from IBM that describes what IBM thinks about RAC. Notice how ‘gloves off’ this document is; solid combative stuff from a company, I can only imagine, is not inhibited by court rulings – lucky them!
IBM’s document: A Technical Discussion of High Availability and Crash Recovery:
In the second instance, I’m going to point you to a document from Microsoft that describes what Microsoft cautiously thinks about RAC.
Microsoft’s document: The Reality behind Oracle Real Application Clusters (RAC) Marketing Messages:
Spot the difference in style – amusing isn’t it?
First and foremost I’m a technologist, I am keen to see a balanced discussion and consequently I am all too happy to provide links to Oracle’s rebuttal to both these articles.
Oracle’s rebuttal to IBM’s paper:
Oracle’s rebuttal to Microsoft’s paper:
Again in the interests of fair play, I should point out that Microsoft’s paper has been updated since Oracle wrote their rebuttal.
Go read and form your own opinion.
PS - Thanks to Chris's comment we have some more debate, in his words:
"I thought you might like to know that there has been another paper published on this subject around RAC, availability and suchlike .. very detailed and definitely a (and fair) read:" This white paper from SQL Server Architect James Hamilton discusses the problems that Oracle Real Application Cluster (RAC) is designed to solve, and presents alternative technologies and trends that often increase application availability and scalability in a more effective way.