On Wed, Jan 12, 2011 at 6:51 PM, Tim Starling tstarling@wikimedia.org wrote:
I think this is an exaggeration.
When I optimise the parse time of particular pages, I don't even use my sysadmin access. The best way to do it is to download the page with all its templates using Special:Export, and then to load it into a local wiki.
But how do you determine which templates are causing server load problems? If we could expose enough profiling info to users that they could figure out what's causing load so that they know their optimization work is having an effect, I'd be all for encouraging them to optimize. The problem is that left to their own devices, people who have no idea what they're talking about make up nonsensical server load problems, and there's no way for even fairly technical users to figure out that these people indeed have no idea what they're talking about. If we can expose clear metrics to users, like amount of CPU time used per template, then encouraging them to optimize those specific metrics is certainly a good idea.
Parsing large pages is typically CPU-dominated, so you can get a very good approximation without simulating the whole network.
Templates that use a lot of CPU time cause user-visible latency in addition to server load, and WP:PERF already says it's okay to try optimizing clear user-visible problems (although it could be less equivocal about it).