Wikipedia:Wikipedia Signpost/2012-07-09/Technology report

Technology report

Optimism over LastModified and MoodBar, but change in clock time causes downtime

LastModified trial results are in

The "page last modified" display with the LastModified extension disabled...

The results from last month's trial of the LastModified extension were published this week on the Wikimedia blog. The first analyses have indicated a significant positive impact, suggesting that the extension – which makes the time since a page's last edit much more prominent in the interface – could eventually find its way onto Wikimedia wikis.

This more prominent display (see right) was added to some 20,000 English Wikipedia articles, linking directly to the full revision history. The results of this trial were nevertheless surprising: rather than click on the new timestamp, visitors preferred to click directly on the history tab, indicating salience of its location. "The increase was particularly strong for anonymous editors and readers, who landed on the history page more than twice as often (+120.6%) [as the control sample]", explained Steven Walling, on behalf of the Foundation's editor engagement experiments (E3) team. "For registered users, there was a smaller but still significant increase in article history views (+42%). This result was seen even when we controlled for repeat clicks on either link".

Despite this apparently positive result, Foundation developers (perhaps feeling the effect of recent controversies) seem wary of pushing the extension onto communities for the moment. Anonymised data has been released, but thereafter the E3 team will simply move onto new experiments – such as "transforming this timestamp into a more direct call to edit articles that are severely outdated, though clearly the point at which an article becomes out of date is somewhat subjective" – rather than handing over the extension to a deployment focused team.

Also published this week was an extensive analysis of the impact of the already-deployed MoodBar extension. That research, also suggestive of a broadly positive impact, is expected to be followed up with a further study to eliminate the possibility of selection bias.

Leap second causes problems

"At midnight UTC on July 1, Wikimedia’s search cluster stopped working" (Wikimedia blog). The proximal cause was surprising: the insertion of a single leap second, so that June 30 officially had 86,401 seconds rather than the usual 86,400. This caused significant problems, not just on Wikimedia wikis but across the web, affecting sites such as Reddit, Foursquare and LinkedIn. Wikimedia's search services were restored in slightly less than two hours.

As Lead Platform Architect Tim Starling explained, "leap seconds are added to our clocks once every few years so that the sun will be directly overhead of the Royal Observatory in Greenwich at precisely 12:00. Some people believe that the desire to keep these two time standards synchronised is anachronistic, and that it would be better to let them drift apart for 600 years and then add a single “leap hour”. I’m sure many computer engineers would breathe a sigh of relief if such a change were implemented."

A knock on, more general problem was finally resolved on July 2 following technical work by the WMF's network operations team (wikitech-l mailing list). Given that those problems seem to have affected the Foundation's servers hosted only in Tampa, Florida (and not their Ashburn, Virginia counterparts), the implication is that ageing hardware that is expensive to replace could have exacerbated the problem. The Signpost hopes to publish an interview with a member of the operations team about this and other recent issues in the near future.

In brief

Signpost poll

HTML5

You can now give your opinion on next week's poll: Which of these best sums up your view about the recent performance of Wikimedia wikis? Last week's poll result has also been slightly corrected.

Not all fixes may have gone live to WMF sites at the time of writing; some may not be scheduled to go live for several weeks.

MediaWiki 1.20wmf7 begins deployment cycle: 1.20wmf7 – the seventh release to Wikimedia wikis from the 1.20 branch – was deployed to its first wikis on July 9 and will be deployed to all wikis by July 18. The release incorporates some 250 changes to the MediaWiki software that powers Wikipedia, comprising 130 "core" changes and 120 changes to affected WMF-deployed extensions. Among the changes (themselves the production of some two week's worth of development time) are a fix for date sorting in tables and a raft of edits to the Visual Editor prototype released last month. A release to external sites including the same selection of bug fixes and new features is not expected for some time.
Wikimania looms: Wikimania, an annual conference targeted at Wikimedians and often well attended by those with a technical slant, will be held in Washington DC later this week. Preceding the event is a "beginner friendly" hackathon (July 10–11) to include both development-focussed activities and guidance for those wishing to "contribute without programming". Wikimania itself (July 12–14) will host 14 wholly (and an additional half-dozen partially) technology-focussed sessions of 80 minutes each, with the possibility of conflict. Each session will include two or three talks or workshops, the pick of which include community engagement (1, 2); operations and performance (1, 2); Wikipedia mobile; Wikidata; Visual Editor; Athena (a possible successor to the Vector skin, announced in November last year) and an "Ask the Developers" panel. A room has also been arranged for technology conversations to continue on July 15 during the "unconference" period of Wikimania. There will be a review of Wikimania talks in next week's Signpost.
Wikidata vote announced: Voting is now open to choose a logo for the Wikidata project and its eventual data repository (Wikimedia Deutschland blog). Voters (essentially all Wikimedians are eligible to vote) can choose from more than 30 designs selected by the Wikidata team from an original pool of 70 user-generated submissions. Voting is open until July 12 at 23:59 UTC, with the result announced on July 13, in time for next week's edition of the Signpost.
Kiwix, Lua investigated: Gerard Meijssen this week published an interview on his personal blog with Emmanuel, one of the developers behind Kiwix, an offline Wikipedia reader that has received WMF support since early 2011 (see previous Signpost coverage). As Emmanuel explained "Kiwix [allows] people to read Web contents without an internet connection. ... It's used to access Wikipedia offline, by reading pre-packaged Wikipedia ZIM files [and is] mainly used by people who want to have an encyclopedia, but are too poor to have [consistent] access to the internet." The interview touched on the current Kiwix setup and possible future developments with the software. For the official Wikimedia blog, Meijssen interviewed Derk-Jan Hartman (User:TheDJ) about his experience trying out the forthcoming support for parsing scripts written in programming language Lua at last month's Berlin Hackathon (see previous Signpost coverage).
Unique contributor figures standardised, revised upwards: Following a thread on the wikitech-l mailing list, unique MediaWiki code contributor counts for the last few months have been updated to reflect a new, standardised way of obtaining the figures. Specifically, as a result of that improved methodology, April's figure was revised upwards from 53 to 67, while May's soared from 41 to 77. The revisions go a long way to explaining the post Git switchover drop in the number of unique contributors to MediaWiki; the unofficial figure for June (92), buoyed by the Berlin hackathon, is broadly comparable to pre-switchover figures.
Gerrit upgraded: MediaWiki code review system Gerrit was upgraded this week from version 2.3 to 2.4.2 this week (wikitech-l mailing list). Announcing the change, WMF developer Chad Horohoe highlighted "the new 'Rebase' button, which will hopefully make it easier to rebase your changes against your branch without having to download the change first". In related news, developers also discussed Gerrit's "sandbox" feature, also enabled by Horohoe this week (also wikitech-l). The feature, which is currently live, allows users a personal space in which to host code not yet suitable for official review.
Bots approved: 3 BRFAs were recently approved for use on the English Wikipedia:
- Robert SkyBot's 5th BRfA, changing "Reference" to "References" and "External link" to "External links" in section headers;