Wikimedia engineering May 2013 report

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Major news in May include:

Note: We’re also providing a shorter, simpler and translatable version of this report that does not assume specialized technical knowledge.

Engineering metrics in May:

  • 124 unique committers contributed patchsets of code to MediaWiki.
  • The total number of unresolved commits went from about 815 to 960.
  • About 87 shell requests were processed.
  • Wikimedia Labs now hosts 165 projects and 1382 users; to date 1943 instances have been created.


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Technical Operations

Site infrastructure

The migration to MariaDB continued, with Wikimedia Commons now fully moved over. Additional database infrastructure work was completed in support of the Tool Labs, producing a row-based replication stream with all PII removed for the publicly accessible Tool Labs databases.
We’ll be upgrading to Request Tracker version 4 and migrating the service to Eqiad soon. Most of the ground work is laid for this; RT4 is puppetized and we’ve done a dry run.
Brandon Black made improvements to our Varnish cache invalidation code. Together with Mark Bergsma and Faidon Liambotis, they wrote a replacement for varnishhtcpd called vhtcpd, and deployed it to the production Varnish machines. The new daemon is ~50x more efficient at the same basic job. This buys us some performance on Varnish machines in general, but more importantly it gets rid of invalidation failures due to network buffer overruns when the old daemon couldn’t keep up. This should also rid us from the random software failures in the old daemon that resulted in missing some or all cache purge requests for extended periods of time. The initial deployment has just been a basic swap of the two daemons. Further near-future improvements include turning on the new daemon’s HTCP regex filtering configuration for more efficiency gains, and tying its HTCP packet statistics back into our normal monitoring and analysis infrastructure, so that we can better see any further multicast invalidation delivery issues that may arise.
Daniel Zahn led the OS patch release train; the team has started to upgrade about 50% of the servers to-date and will finish the rest in June.
Faidon also worked with Aaron Schulz and made Ceph at Eqiad the primary media storage back-end, leaving Swift at Tampa as a secondary fail-over back-end. This means that MediaWiki application servers were writing to & reading from there for about four & two weeks respectively. More recently, the cluster encountered some problems and traffic was temporarily reverted back to Tampa. Faidon is now upgrading Ceph software to the newer upstream version, Cuttlefish, which addresses a number of problems that were encountered during this time and were successfully reported to Ceph developers. Testing will resume after that happens, both by re-enabling Ceph as a MediaWiki back-end and by switching a portion of Varnish traffic to Ceph.
Mark and Faidon started working on migrating the Text Squid servers to use Varnish instead. In Mark’s preliminary tests on 1 Esams and 4 Eqiad servers, the results look encouraging. He will start adding more traffic to them in the coming weeks.

Data Dumps

The routine dumps of Wikidata ran into two roadblocks, one of them related to the way that Recent changes patrol and autopatrolling are handled in MediaWiki. While a local workaround is in place, there has been discussion of revamping the patrolling mechanism including changes to the database [1]. The other issue, affecting the full history content dumps, also has a temporary workaround until we can decide what the meaning of the rev_len field in the database for revisions really means.
The mwxml2sql utils have been through some testing and bug fixes, and a volunteer is interested in packaging them for Debian to accompany his code for local installation of a mirror of Wikipedia (or the project of one’s choice).
Incremental dumps will be developed this summer by User:Svick as part of this year’s GSoC program. We’re happy to have him and can’t wait for the finished code!

Wikimedia Labs

This month was mostly dedicated to bringing Tool Labs online, but a number of other changes occurred as well. Work has progressed on AJAXification of the OpenStackManager interface. Instance reboot actions are now using this and there are gerrit changes awaiting review for instance console output, instance deletion, and some IP address actions. The custom virtual machine image had a number of fixes this month improving reliability and boot speed. We expect further improvements with upgrades to the OpenStack grizzly or havana releases. OpenStack was upgraded from the essex release to the folsom release, increasing speed of operations and bringing some new features (such as instance resizing). We’ll be making these features available for use soon. All virtualization hosts and all instances were upgraded for a kernel security vulnerability and were rebooted this month, causing roughly an hour of scheduled downtime. Work has also been progressing on creating instances pre-configured for doing MediaWiki development; this has been working in the past, but it is now more reliable, faster, and meets our legal team’s requirements for MediaWiki installations in Labs. Work has also progressed on a more reliable development environment for Labs itself. Soon it should be possible to install a pre-configured instance ready for making changes to the Labs infrastructure.
Tool Labs is now operational, with roughly 150 tools already migrated. With the completion of the basics of replication (all but s7 are operational), there remains no roadblocks for migration. During the week since the Amsterdam Hackaton, a fair number of minor issues have been found and fixed, and the general consensus from users is that the environment is functional. On the roadmap for the next month is cleaning up some of the management for replication (so that it is more generalized), finish s7, and help users with their migration issues.
Tool Labs work has also added a new feature available to all of Labs: service groups. Service groups are a user/group combination available locally within a project. Service group membership allows regular users to sudo to the service groups, allowing per-project service users, rather than needing to create local users via puppet, or create global users via wikitech.
Work progresses on puppetizing more OpenStack services and the OpenStackManager extension. Currently OSM development is hampered by a lack of test installs; soon we should have the ability to easily create new labs instances running Openstack and OpenStackManager for testing and development.

Features Engineering

Editor retention: Editing tools


In May, the VisualEditor team worked to complete the major new features we have prioritised over the past few months. Our objective is for VisualEditor to be the default editor for all Wikipedia users, capable of letting them edit the majority of content without needing to use the wikitext editor, in July 2013. We have focussed on four areas of new functionality: adding and editing inclusions of references, templates, categories and media items. Our main area of work over the past month has been on references and templates, and we now have implemented editing them in our experimental code; category editing is nearly complete and should be made available very soon. The deployed alpha version of VisualEditor was updated twice (1.22-wmf4 and 1.22-wmf5), adding a number of user interface improvements, including further work on the back-end to better support the new features, and fixing a number of bugs.


In May, the Parsoid team implemented several new features, as well as important performance optimizations in preparation for the July VisualEditor release.
A major image handling overhaul enabled rendering and editing of all image-related parameters with a relatively simple DOM structure. Template and extension editing was improved to support editing of templates within extensions. This lets editors modify and add templated citations in VisualEditor, an important feature to improve the quality of articles in Wikipedia.
On the performance front, we are now reusing expensive template, extension and image expansions from our own previous output to avoid most API queries after an edit. This is necessary to avoid overloading the API when tracking all edits on Wikimedia projects. A cache infrastructure with appropriate purging was set up and will be tested at full load through June.
At the Amsterdam hackathon, we helped developers leverage our rich HTML+RDFa DOM output for projects like a Wikipedia-to-SMS service or the Kiwix offline Wikipedia reader.

Editor engagement features


In May, we released new features and bug fixes for Notifications on the English Wikipedia and Ryan Kaldari, Vibha Bamba and Fabrice Florin collaborated with community members to develop a ‘new message indicator’, to inform users when someone posts on their talk page. The team also released a new ‘Thanks notification‘ that lets editors show their appreciation to users who make helpful edits, and offers a quick way to give positive feedback on Wikipedia. Benny Situ developed a feature that marks messages as read when you visit your talk page and expanded our first metrics dashboards, in collaboration with Dario Taraborelli and Aaron Halfaker. New team member Erik Bernhardson developed several new features, such as updating talk page notifications to link directly to their sections. Luke Welling continued to develop HTML Email notifications. Fabrice Florin worked with Oliver Keyes to discuss this product with a wide range of community members, and led the team to plan the next steps for Notifications and other editor engagement features. To learn more, visit the project portal, read the FAQ page and join the discussion on the talk page.

Article feedback

In May, we developed a few last features and bug fixes on the English, French and German Wikipedias. As requested by community members, Matthias Mullie developed a new opt-in feature that makes it easier to enable or disable feedback on a page, as well as new UI improvements to simplify the feedback page, based on designs by Pau Giner and specifications by Fabrice Florin. The team also released new feedback links and tested the auto-archive feature on prototype. For tips on how to use Article feedback, visit the testing page, and let us know what you think on this talk page. Feature development has now ended for this project, and we will determine our next steps based on the upcoming community vote on the German Wikipedia in coming weeks.


Discussion portals were announced and opened on three wikis: the English Wikipedia, Meta-Wiki, and An interactive prototype was released to the public for discussion. Discussion is on-going, and the definition of the “minimum viable product” is being worked on.

Editor engagement experiments

Editor engagement experiments

In May, the Editor Engagement Experiments team (E3) launched its redesigns of account creation and login forms, after numerous bug fixes and working with local communities to customize the interface as needed. The initial rollout was to 30 of the largest Wikimedia projects in English and other languages, including Wikipedia, Wikimedia Commons, Wikidata, Wikivoyage, Wikispecies, Wikiquote, Wiktionary, Wikibooks, Wikiversity and Wikisource. Complete deployment as the default for all remaining projects was enabled early in June.
Also this month, the team launched and tested a major revamp of the “Getting Started” interface for onboarding new Wikipedians (in English). This included a redesigned landing page, a refactor of the backend to increase speed and stability, a new navigation toolbar on articles that new users were given as their first editing task, and a guided tour to help them complete their first edit. The results of A/B testing of this new version showed the largest increase in click-through rates for the landing page – up to 32%, a large increase over the 10-12% click-through rate of previous versions. Overall, it also showed a small but statistically significant increase in the rate of first time edits (+1.7%) by new English Wikipedians invited to participate in Getting Started.
Last but not least, the PostEdit extension (previously enabled on most of the top Wikimedia projects by size) was migrated to MediaWiki core. With this change, the post-edit confirmation message will be available on all projects, and will be more easily integrated in to VisualEditor.


2012 Wikimedia fundraiser

The Operations team moved db1025 into the firewalled fundraising cluster (frack), rebuilt it on Precise with MariaDB. RAID monitoring tools were updated to support RAID controllers used in frack. We’ve mostly finished building/puppetizing the new payments listener (thulium) as well as a new CiviCRM host (barium), both of which are in frack.

Language engineering

Language tools

The last round of major bugs have been fixed in the Universal Language Selector (ULS) before we start phased its deployment over the month of June across hundreds of Wikimedia websites. Communications announcements have been started for the first phase of deployment which includes removal of Narayam and WebFonts from sites before ULS is rolled out with the same integrated feature set. Test scenarios for ULS have been identified in detail. Implementation of automated tests is in progress. A combination of ULS integration and cross browser testing is in progress. Final performance tweaks are in progress before we get ready to launch the redesigned home page of in June. The monthly version of the Mediawiki Language Extension Bundle (MLEB) was released on May 29.


jQuery.webfonts and jQuery.IME continue to be in maintenance mode with new input methods added to our repository this month. jQuery.ULS is being actively updated to reflect design changes suggested by the Product team as well as bug fixes.

Language Engineering Communications and Outreach

The Language Mavens met and discussed areas they can contribute to for Language tools. As part of GSoC 2013, all developers on the team are set to mentor 4 Language Engineering projects supporting jQuery.IME, Language Coverage Matrix, RTL support for Visual Editor and Translate mobile app. Monthly office hours and bug triage were held. The team continued to report and blog on its activities. Hackathon organization and participation at Amsterdam and Tel Aviv were very successful.


Wikipedia Zero

This month, the team launched Wikipedia Zero with Mobilink in Pakistan, refactored legacy codebase, migrated configuration from monolithic wiki articles to per-carrier JSON configuration blobs, generated utility scripts, patched legacy hyperlink redirect and content rendering bugs, and supported partner on-boarding.

Mobile Web Photo Upload

This month, we’ve pushed the ‘Nearby’ view to the stable version of the mobile site. Now, with a location-aware device, you can easily identify articles close to your current location. We’ve also made ongoing improvements to photo uploads and the photo upload experience, including improved messaging around image quality and copyright requirements for new uploaders in the beta version of the mobile site. The upload features in general have been a great success, as we’ve sustained over 1000 unique uploaders over the last two months. We are continuing to experiment in the beta version of the site with improvements to article editing, an improved reorganization of site navigation, Echo notifications, talk pages, and simplifying discovery of article actions (eg editing and watching). We plan to launch these beta features over the course of the next month.

Platform Engineering

MediaWiki Core

MediaWiki 1.21

MediaWiki 1.21.0 was released, followed by a MediaWiki 1.21.1 maintenance release.

MediaWiki 1.22

MediaWiki 1.22wmf3, wmf4, and wmf5 were deployed to Wikimedia sites during the month of May. This included one breaking change, gerrit change 49364.


After deploying Score in April, various performance improvements and fixes were merged in May. To improve scaling of large images, the VipsScaler extension was prepared on the cluster and is ready for deployment in the next weeks. TimedMediaHandler had various bug fixes and the libraries used to encode WebM videos were updated to improve quality and address encoding issues.

Wikidata deployment

Wikidata continued to roll out updates to the client (what lives on the various project wikis) and repository (what powers software; see the wikidata newsletter for more information: May 3rd and May 24th. Additionally, there was Operations-related work to create helpful URL redirects for entity matching along with fixes to the logging of autopatrolled edits (which was causing massive database usage and issues when doing archival dumps). These URL redirects and autopatrol fixes should go out in June.

Site performance and architecture

Many MediaWiki developers met in Amsterdam to discuss architectural principles and the RFC process.

Admin tools development

This month the team worked on Single User Login finalisation, which will mean that all user accounts will be global across all of Wikimedia’s public wikis, and so allowing for cross-wiki notifications and better tools for editors. This will require all user accounts to be uniquely named and not conflict with other accounts. Some more work was done on the global account renaming tool. The team attended the Wikimedia Hackathon 2013 in Amsterdam where we discussed issues with admin tools and plans for the future with a number of volunteer developers.

Security auditing and response

We released MediaWiki 1.20.6/1.19.7 and provided security training for developers at the Amsterdam Hackathon.

HipHop deployment

Several engineers at the Wikimedia Foundation met with Facebook engineers to discuss potential deployment of HHVM in 2013 (summary). We formed the HipHop mailing list to discuss moving forward with this work.

Quality assurance

Quality Assurance

In May, QA worked with a number of parties both in and outside the Wikimedia Foundation to test Echo, VisualEditor, Universal Language Selector, and other projects. We began an official QA mailing list.

Beta cluster

In May, Ariel Glenn helped out setting up missing bits of infrastructure to the beta cluster. He added a Redis instance (that holds the job information) and HTTPS support. HTTPS will let us write scenarios related to logging in on the wiki or via a mobile device; it will also let us test out OAuth.
udp2log archiving is now working reliably. Max Semenik has set up an EventLogging infrastructure on beta, and Niklas Laxström enabled Universal Language Selector. The Job processing was malfunctioning but was restored.
Since April 30, the MediaWiki instances are using NFS, which is much faster than the previous GlusterFS share; pages serving time went from 560 ms to 260 ms.
Roan Kattouw has deployed Parsoid and VisualEditor on beta. Just like in production, users can enable it in your their preferences under ‘Editing’.

Continuous integration

In the beginning of May, Jenkins/Zuul faced overload for a few days; this was resolved by upgrading Zuul and tweaking some time-expensive part of the code. Zuul now lets us define which jobs it triggers by using a predefined template which makes it easier to add new projects. Zuul is now faster to report changes back to Gerrit, which was a complaint during rush hours.
The Wikibase client and repo components are now tested in Jenkins. All puppet repositories are now verifying the puppet manifests and erb templates for syntax validity. The Qunit tests being run for MediaWiki core and VisualEditor seem to be in good shape.
PHP CodeSniffer has been upgraded as well as the standard for MediaWiki code. We have yet to enforce it though, since the current code base does not pass the standard.

Browser testing

In May, we added beta labs as a target for automated browser tests, which allowed us to create tests for the Universal Language Selector at the Hackathon in Amsterdam. We shored up a lot of Jenkins builds at the hackathon as well. We created our first test for VisualEditor, and we are looking forward to working with Rachel Thomas (as part of the Outreach Program for Women) to create more.


Analytics infrastructure

We continued our efforts of increasing our monitor coverage of the different webrequest dataflows. On the udp2log side, we added monitoring per DC/server role. Every month, we work on improving the robustness and security of the analytics-related servers that we run: we moved the multicast relay from Oxygen to Gadolinium, we upgraded Oxygen to Ubuntu Precise, and we moved all the Limn-based dashboards from the Kripke labs instance to the Limn0 labs instance. Continous integration for webstatscollector, wikistats and udp-filters now works. The puppet module for Hadoop has been merged in the Operations reposotiry; this is a big step forward in moving Kraken from beta to production status. Magnus Edenhill demonstrated varnishkafka based on Kafka 0.8; on a local machine varniskafka was able to process 140k msgs/s and we are planning to do production testing mid June. Last, we separated the Kraken machines from the other production servers by installing network ACLs.

Analytics Visualization, Reporting & Applications

For the mobile team, we started collecting pageview counts for both official and non-official Wikipedia apps. We changed our Kafka import configuration so that the raw webrequest folders are directly queryable using Hive. The decision was made to re-platform the UMAPI codebase; we have spent quite some time specifying user stories and had productive discussions about the architecture during the Amsterdam Hackathon. On the development side, the ‘page count’ metric was introduced. We adapted Ori Livneh’s Mediawiki Vagrant VM to also support UMAPI in combination with test data. This will make it much easier to debug issues and open development up to community members. We also fixed numerous stability bugs.

Engineering community team

Bug management

A Wikimedia Labs instance to test Bugzilla software changes and a patch to puppetize Bugzilla are now available (thanks to Ori Livneh). This will make updating Bugzilla to newer versions and reapplying Wikimedia’s custom patches much easier. A MediaWiki Installer bugday took place in preparation of the MediaWiki 1.21 release, as well as an IRC office hour. Andre Klapper worked on a proposal for a Bugzilla admin policy. In Bugzilla’s configuration, the number of Bugzilla administrators has been decreased in order to improve coordination. As a side-effect of his investigation, Andre documented the meaning of Bugzilla admin rights.

Mentorship programs

We selected 20 Google Summer of Code and 2 Outreach Program for Women projects that will be mentored by a total of 32 volunteers. This represents more than double the amount of projects we had last year. We received 69 applications from 60 students for Google Summer of Code 2013, from which 9 were also applying to OPW, and 4 OPW-only individual applications. Google allocated the 21 slots we requested, but we decided to give one back in order to keep a standard on project feasibility.

Technical communications

In May, Guillaume Paumier‘s major focus was on supporting Tech ambassadors and setting up Tech news, an initiative aiming to collaboratively monitor recent software changes likely to impact Wikimedians, and distribute a weekly summary, free of technical jargon, to subscribers on their talk page. Two issues of this weekly summary were published this month; starting with the second issue, the content is now distributed in several languages if translations are available. Guillaume also continued to review technical blog posts, and executed the move of the Mobile documentation from Meta-Wiki to

Volunteer coordination and outreach

Quim Gil has been preparing a proposal to get automated community metrics based on vizGrimoire and provided by their maintainers, Bitergia. It is currently being discussed with Sumana Harihareswara and Rob Lanphier for budget approval. Quim also worked on a user-friendly template for the landing page of the wikitech-announce mailing list that can be used for other Wikimedia lists (source code). He also created a landing page for organizations willing to collaborate with Wikimedia to co-organize technical activities.


The Kiwix project is funded and executed by Wikimedia CH.

With openZIM, we have finally released the first version of its standard implementation code: the zimlib. Kiwix was introduced in Debian testing. A new release of Kiwix for Android, with a few bug fixes and improvements, was released. Our first GSoC project (ZIM incremental updates for Kiwix) was prepared and accepted; work has already started with Kiran, the Indian student responsible for this project.


The Wikidata project is funded and executed by Wikimedia Deutschland.

The Wikidata team worked on 2 major topics in May: the ability to access data from Wikidata in a Wikipedia article by its label and not just its ID, and the ability to enter points in time into Wikidata, which for example now makes it possible to enter the date of birth of a person. Magnus Manske blogged about the tool ecosystem that is building around Wikidata. During the next 3 months, the team will be working with 3 Google Summer of Code students, and 2 other students will be working with other organizations on Wikidata-related projects. The codebase has been reviewed by Qafoo. Wikidata-tech, a new mailing list for discussions related to the development around Wikidata, was created. Additionally, the team attended the hackathon in Amsterdam to give tutorials and meet other developers. A prototype of a multilingual map was built there, among other things.


The engineering management team continues to update the Deployments page weekly, providing up-to-date information on the upcoming deployments to Wikimedia sites, as well as the engineering roadmap, listing ongoing and future Wikimedia engineering efforts.

This article was written collaboratively by Wikimedia engineers and managers. See revision history and associated status pages. A wiki version is also available.

Archive notice: This is an archived post from, which operated under different editorial and content guidelines than Diff.

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