On 11/29/07, Steve Bennett <stevagewp(a)gmail.com> wrote: Yes, they're run from a single set of files stored on NFS (which are synchronized with the various Apaches by using the scap utility). The differences between sites, such as different databases and settings, are handled by, effectively, a single LocalSettings.php equivalent with conditionals based on the Host in the request. The way large changes are usually handled is small-scale testing (on non-content wikis like private wikis or maybe test.wikipedia.org) followed by rolling out on all sites, and if necessary reverting that and doing more small-scale testing. I imagine it's not considered acceptable to have code with possibly major bugs running on even small sites, and if you think it's not buggy, best to test that by as wide a deployment as possible. The problems with the new parser were detected within minutes by a flood of English-speaking users from major wikis coming into #wikimedia-tech: how long would it have taken if we only rolled it out on some of the tiny wikis?