On 05/03/07, Tim Starling tstarling@wikimedia.org wrote:
I said "In Tampa there's lots of big disks, these go to three big database servers - one for English Wikipedia, two for the other 200+ projects - and these go to hundreds of webservers and caches and proxies in Tampa, Paris, Amsterdam and Seoul." Is that about right as a one-sentence description of our setup?
It's close. There are three master database servers, but they're not any bigger than the 12 or so slave database servers, so it might be more accurate to just say that we have 15 database servers. Caches aren't on dedicated servers, so I would say "webservers and caching proxies" rather than "webservers and caches and proxies", leaving the role of the various backend caches unsaid. We no longer have any active servers in Paris.
"A bunch of disks serving three master database servers - one for English Wikipedia, two for the other 200+ projects - going to hundreds of webservers and proxy servers around the world, in Tampa, Amsterdam and Seoul."
The DB split is useful info because en:wp is such a huge bugger.
A tier you didn't mention, which the journalist may or may not find interesting, is that our load balancing frontend is LVS-DR on commodity servers, with geographic DNS to balance between clusters.
He was going "wow" about a non-profit running a top-10 site on no money, and it was the best not-quite-technical answer I could give him that I thought would be reasonably robust against a journalistic game of telephone :-)
- d.