MediaWiki talk:Recentchangestext

DPL not permitted on this page
Hey guys, I'm a member of Wikia's Community Engineering team, working to help keep our communities happy & our servers healthy. We've noticed your Special:Recentchanges page in our logs of slow pages, so I came in to investigate and decided to remove your DynamicPageList (DPL) calls from that page. Let me explain why.

DynamicPageList can be, depending on the query and parameters specified, anywhere from fast through slow to downright dangerous to Wikia as a whole in terms of affecting site performance (and the ability of our servers to respond to requests).

We allow DPL to be used, despite the dangers, because it is a very powerful tool for Wikians to enhance their wikias and save themselves some time.

We do that assuming, that even the most dangerous DPL call will be executed once, and then held in parser cache and other caching layers we have in place. That's what happens on a normal article page: you hit save, the server prepares the DPL results once, and stores them. And we're pretty much safe, even if the calculations needed to produce the results are very complex.

Special pages, like RecentChanges, work differently. By their very nature they need to be current, and so cannot be cached. By putting a DPL call on RecentChanges you cause it to be executed in full every time.

This results in RecentChanges being at times very, very slow (our slow log shows times well above 15 seconds, while the normal Wikia average is about 250 milliseconds).

Given all this, I hope you'll understand that DPL cannot be included in Recentchangestext. Please handle adding links to this message manually.

Thanks for your understanding.

Happy editing,

TOR (talk) 14:37, February 23, 2014 (UTC)