On 6/1/07, Joshua D. Drake <jd@xxxxxxxxxxxxxxxxx> wrote:
Alexander Staubo wrote: > You mean aside from the obvious one, scalability? Multimaster doesn't give you scalability (at least not like a lot of people think it does).
That depends on your particular definition of multimaster.
Databases are a bottleneck when you get a bunch of so called web 2.0 developers thinking they know an inch about databases.
That's a fairly bizarre and disrespectful blanket statement that includes some good friends of mine, and probably many of people on this list. I wonder you what you mean by it; regardless of the type of application, a single machine has a very real, very finite number of transactions it can process per second, and a finite number of spindles you can attach to it. No amount of handwaving about the incompetence of others changes that. Note that I am not talking about multimaster replication here, just scalability. Like Andrew Sullivan I think multimaster replication is infeasible by design, at least with a system such as PostgreSQL.
What you are basically saying below is... web 2.0 developers such as rails developers have so fundamentally broken the way it is supposed to be done, we should too...
I don't know if I said that, but I would love to hear how they have broken it, and what you propose the solution to be. The eBay architecture is one interesting example, demonstrating a situation where no single box could possibly handle an entire database. Their requirements are extreme, but there are much smaller datasets and applications with similar performance characteristics that easily saturate a single box, so at a high level the same principles apply. http://glinden.blogspot.com/2006/12/talk-on-ebay-architecture.html The MySpace scaling story is similarly interesting, if mostly because of the egregious blunders made underway: http://www.baselinemag.com/article2/0,1540,2082921,00.asp You could argue that they solved the problems in an inelegant, irrelational way, but it seems that they solved it, and this is reflected on their balance sheets, which in the end is probably the most appropriate metric of success. Alexander.
