Last modified: 2008-09-11 16:42:24 UTC
At the moment, many pages are exceeding the proposed #ifexist per-page limit of 100. (Currently this limit is set to 2000, which is already exceeded by some pages). I predict that on the day the new proposed limit is put into operation, some pages will silently break, and there will be tons of "omg!!!111oneone Y my [[page]] doesn't work???77"-like flood in #mediawiki or #wikimedia-tech, and many more editors will be at least confused.
So, after the short discussion with Tim Starling, I propose the following:
* If the amount of #ifexist usage on the page is less or equal to 100, it should be indicated only by a comment at the bottom of the rendered HTML (as it is now).
* Otherwise, if it's greater than 100, the warning should be put just before the categories (making it always visible). For &live, the message should go to the very end of output. This warning should be big and red, and a message (I propose to name it [[MediaWiki:ifexist-limit-exceeded]]) with $1 and $2 for usage amount and limit would be nice.
I've set the bug priority to high, because I think that this should be done before the limit is lowered.
This seems like a good idea; however, I suggest that it should be not just for the #ifexist limits but for the other template limits as well (pre-expand include limit in particular); when a page stops working, it's useful to inform users why. It could say something like "Warning: this page has not been processed correctly because it was too complicated: more than 100 #ifexists on page", changing the reason as appropriate.
Proposed solution in r28336/r28337: warning on preview plus place the page in a category.
Solution implemented and commited, available since 1.12, the improved version has already been deployed on Wikimedia servers (see e.g. http://en.wikipedia.org/wiki/Category:Pages_with_too_many_expensive_parser_function_calls). Marking as RESOLVED FIXED.