Re: [Analytics] Drop in Commons mobile traffic - a diagnosis

Yes, this has been an issue before. Squid log based reports filter these banners for years, but only after a similar distortion became very apparent, and a lot of data needed to be repaired. -----Original Message----- From: analytics-bounces(a)lists.wikimedia.org [mailto:analytics-bounces@lists.wikimedia.org] On Behalf Of Oliver Keyes Sent: Friday, February 06, 2015 22:04 To: A mailing list for the Analytics Team at WMF and everybody who has an interest in Wikipedia and analytics. Subject: [Analytics] Drop in Commons mobile traffic - a diagnosis Hey all, The pageviews stored at stats.wikimedia.org and the Vital Signs dashboards showed a substantial drop in pageviews to Wikimedia Commons, primarily from mobile, beginning on 1 January 2015. I was tasked with investigating and I'm reporting what I found so that we have a note of the problems this brings up. From an investigation of requests to that site at that time, it appears that this is a perfect storm of known deficiencies in the legacy pageviews definition, fundraising changes, and mobile changes. To summarise: 1. The legacy Pageviews definition contains Special pages, including Special:BannerRandom and Special:HideBanner; 2. The mobile website was historically loading things from Commons in such a way as to trigger calls to Special:HideBanner, which were picked up by the legacy definition as "pageviews to commons"; 3. The Mobile team deployed changes to their image loading setup at the end of December that stopped this from happening, and that coincided with the disabling of the Fundraising primary campaign. 4. The result of this was an apparent massive drop in traffic to Commons from the mobile site - when the actual inaccuracy was the inclusion of that traffic in the first place. There are several lessons to be learned from this. First, it is worth reiterating the deficiencies and inaccuracies inherent in the legacy pageview definition, many (but certainly not all) of which centre on how it treats the fundraising banners. We are working as rapidly as we can to completely deprecate this definition, replacing it with a new one which is not subject to this kind of variation. We are currently in the middle of performing final QA testing on the new definition: once it is satisfactory, we will deploy it as soon as humanly possible and deprecate the legacy definition. Second, let me emphasise how critical it is that the teams building MediaWiki and our instances of it - Platform, Operations, Mobile, you name it - keep us in the loop about changes that they make. This was a very dramatic shift in client logic around requests: it flew under our radar. We should have a process in place for letting Analytics know about these changes before they happen so that we do not end up with inaccurate data and a constant game of catchup. Thanks, -- Oliver Keyes Research Analyst Wikimedia Foundation _______________________________________________ Analytics mailing list Analytics(a)lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/analytics _______________________________________________ Analytics mailing list Analytics(a)lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/analytics