Mholloway (Michael Holloway)
Software Engineer, WMF Reading Infrastructure Team

Projects (13)

Today

  • Clear sailing ahead.

Tomorrow

  • Clear sailing ahead.

Thursday

  • Clear sailing ahead.

User Details

User Since
Mar 30 2015, 8:44 PM (203 w, 18 h)
Availability
Available
IRC Nick
mdholloway
LDAP User
Mholloway
MediaWiki User
MHolloway (WMF) [ Global Accounts ]

Recent Activity

Yesterday

Mholloway committed rEWETc5ae92231b09: Add counter for in-app description edits (authored by Mholloway).
Add counter for in-app description edits
Mon, Feb 18, 9:01 PM
Mholloway committed rEWETb7f07b876ad4: Implement counter delays (authored by Mholloway).
Implement counter delays
Mon, Feb 18, 9:01 PM
Mholloway committed rEWET04d01c4a5f4b: Add API meta module ApiQueryWikimediaEditorTasks (authored by Mholloway).
Add API meta module ApiQueryWikimediaEditorTasks
Mon, Feb 18, 9:01 PM
Mholloway committed rEWET5d9935c40fab: Add dev counters (authored by Mholloway).
Add dev counters
Mon, Feb 18, 9:01 PM
Mholloway committed rEWETf892af94c29c: Add unit tests (authored by Mholloway).
Add unit tests
Mon, Feb 18, 9:01 PM
Mholloway committed rEWET8e513a97eb1f: Initial counter groundwork (authored by Mholloway).
Initial counter groundwork
Mon, Feb 18, 9:01 PM
Mholloway committed rEWET09f3f0c7e5d8: Add DB tables for counters (authored by Mholloway).
Add DB tables for counters
Mon, Feb 18, 9:01 PM
Mholloway updated the task description for T216442: Clarify how counter sequencing and resetting (on revert) should work on the backend.
Mon, Feb 18, 8:25 PM · Wikipedia-Android-App-Backlog, Reading-Infrastructure-Team-Backlog (Kanban)
Mholloway committed rEWET28d8471aa886: Add provision for multiple target counts per target (authored by Mholloway).
Add provision for multiple target counts per target
Mon, Feb 18, 8:23 PM
Mholloway updated the task description for T216442: Clarify how counter sequencing and resetting (on revert) should work on the backend.
Mon, Feb 18, 8:23 PM · Wikipedia-Android-App-Backlog, Reading-Infrastructure-Team-Backlog (Kanban)
Mholloway updated the task description for T216442: Clarify how counter sequencing and resetting (on revert) should work on the backend.
Mon, Feb 18, 7:40 PM · Wikipedia-Android-App-Backlog, Reading-Infrastructure-Team-Backlog (Kanban)
Mholloway updated the task description for T216442: Clarify how counter sequencing and resetting (on revert) should work on the backend.
Mon, Feb 18, 7:39 PM · Wikipedia-Android-App-Backlog, Reading-Infrastructure-Team-Backlog (Kanban)
Mholloway updated the task description for T216442: Clarify how counter sequencing and resetting (on revert) should work on the backend.
Mon, Feb 18, 7:39 PM · Wikipedia-Android-App-Backlog, Reading-Infrastructure-Team-Backlog (Kanban)
Mholloway updated the task description for T216442: Clarify how counter sequencing and resetting (on revert) should work on the backend.
Mon, Feb 18, 7:38 PM · Wikipedia-Android-App-Backlog, Reading-Infrastructure-Team-Backlog (Kanban)
Mholloway updated the task description for T216442: Clarify how counter sequencing and resetting (on revert) should work on the backend.
Mon, Feb 18, 7:38 PM · Wikipedia-Android-App-Backlog, Reading-Infrastructure-Team-Backlog (Kanban)
Mholloway updated the task description for T216442: Clarify how counter sequencing and resetting (on revert) should work on the backend.
Mon, Feb 18, 7:37 PM · Wikipedia-Android-App-Backlog, Reading-Infrastructure-Team-Backlog (Kanban)
Mholloway renamed T216442: Clarify how counter sequencing and resetting (on revert) should work on the backend from Clarify how counter resetting (on revert) should work on the backend to Clarify how counter sequencing and resetting (on revert) should work on the backend.
Mon, Feb 18, 7:36 PM · Wikipedia-Android-App-Backlog, Reading-Infrastructure-Team-Backlog (Kanban)
Mholloway moved T216442: Clarify how counter sequencing and resetting (on revert) should work on the backend from To Do to Doing on the Reading-Infrastructure-Team-Backlog (Kanban) board.
Mon, Feb 18, 7:36 PM · Wikipedia-Android-App-Backlog, Reading-Infrastructure-Team-Backlog (Kanban)
Mholloway triaged T216442: Clarify how counter sequencing and resetting (on revert) should work on the backend as High priority.
Mon, Feb 18, 7:35 PM · Wikipedia-Android-App-Backlog, Reading-Infrastructure-Team-Backlog (Kanban)
Mholloway committed rEWETf3fe5b0cdab3: Add provision for multiple target counts per target (authored by Mholloway).
Add provision for multiple target counts per target
Mon, Feb 18, 7:17 PM

Sat, Feb 16

Mholloway closed T216278: Provisioning certain roles breaks prefix-based Vagrant wikifarm proxying in Cloud VPS as Resolved.

The behavior I witnessed here was as described at T207594. It doesn't happen consistently, and does appear consistently fixable by doing vagrant ssh -- sudo service apache2 restart as suggested at https://wikitech.wikimedia.org/wiki/Help:MediaWiki-Vagrant_in_Cloud_VPS#Choose_your_wiki_limbo_state.

Sat, Feb 16, 6:04 PM · Reading-Infrastructure-Team-Backlog, RESTBase, MobileFrontend, MediaWiki-Vagrant

Fri, Feb 15

Mholloway moved T186732: Decide on Cache-Control headers for map tiles from Sign off to To Deploy on the Reading-Infrastructure-Team-Backlog (Kanban) board.
Fri, Feb 15, 9:06 PM · Reading-Infrastructure-Team-Backlog (Kanban), Maps, Traffic, Operations
Mholloway added a comment to T186732: Decide on Cache-Control headers for map tiles.

@Jhernandez Looks like this one has a change waiting to roll out when the Stretch migration is complete, so per our discussion earlier this week let's keep it in To Deploy. Then I think it can be resolved.

Fri, Feb 15, 9:05 PM · Reading-Infrastructure-Team-Backlog (Kanban), Maps, Traffic, Operations
Mholloway created T216278: Provisioning certain roles breaks prefix-based Vagrant wikifarm proxying in Cloud VPS.
Fri, Feb 15, 8:57 PM · Reading-Infrastructure-Team-Backlog, RESTBase, MobileFrontend, MediaWiki-Vagrant
Mholloway committed rEWET4076326bac04: Implement counter delays (authored by Mholloway).
Implement counter delays
Fri, Feb 15, 7:49 PM
Mholloway committed rEWETa44598ce7b4d: Add API meta module ApiQueryWikimediaEditorTasks (authored by Mholloway).
Add API meta module ApiQueryWikimediaEditorTasks
Fri, Feb 15, 7:02 PM
Mholloway committed rEWETd67ba41ee51f: Add counter for in-app description edits (authored by Mholloway).
Add counter for in-app description edits
Fri, Feb 15, 7:02 PM
Mholloway committed rEWET2be160ffbfaa: Add dev counters (authored by Mholloway).
Add dev counters
Fri, Feb 15, 7:02 PM
Mholloway moved T215930: mw.org page for Extension:WikimediaEditorTasks from To Do to Sign off on the Reading-Infrastructure-Team-Backlog (Kanban) board.
Fri, Feb 15, 4:31 PM · Reading-Infrastructure-Team-Backlog (Kanban)
Mholloway triaged T198495: Fix or delete apps-android-wikipedia-periodic-test from CI as Low priority.
Fri, Feb 15, 4:31 PM · Reading-Infrastructure-Team-Backlog (Kanban), Patch-For-Review, Wikipedia-Android-App-Backlog
Mholloway moved T198495: Fix or delete apps-android-wikipedia-periodic-test from CI from Doing to Code Review on the Reading-Infrastructure-Team-Backlog (Kanban) board.
Fri, Feb 15, 4:31 PM · Reading-Infrastructure-Team-Backlog (Kanban), Patch-For-Review, Wikipedia-Android-App-Backlog
Mholloway edited P8088 sites table example.
Fri, Feb 15, 4:27 PM
Mholloway created P8088 sites table example.
Fri, Feb 15, 4:27 PM

Thu, Feb 14

Mholloway committed rEWET0fb95b22f1db: Add API meta module ApiQueryWikimediaEditorTasks (authored by Mholloway).
Add API meta module ApiQueryWikimediaEditorTasks
Thu, Feb 14, 11:56 PM
Mholloway committed rEWETaf40bd67fa4f: Add API module ApiWikimediaEditorTasks (authored by Mholloway).
Add API module ApiWikimediaEditorTasks
Thu, Feb 14, 11:24 PM
Mholloway committed rEWET5eef3f4e723b: Add dev counters (authored by Mholloway).
Add dev counters
Thu, Feb 14, 11:24 PM
Mholloway added a comment to T216191: Replace Istanbul with nyc.

Removed the linked patch next to mobileapps, which was unrelated unless I'm missing something.

Thu, Feb 14, 10:26 PM · Core Platform Team Kanban, Services (next)
Mholloway updated the task description for T216191: Replace Istanbul with nyc.
Thu, Feb 14, 10:26 PM · Core Platform Team Kanban, Services (next)
Mholloway committed rEWETa18cd5a16043: Add API module ApiWikimediaEditorTasks (authored by Mholloway).
Add API module ApiWikimediaEditorTasks
Thu, Feb 14, 12:26 AM
Mholloway committed rEWET47f4a21e2e22: Add dev counters (authored by Mholloway).
Add dev counters
Thu, Feb 14, 12:26 AM
Mholloway committed rEWETe5b09d207e9c: Initial counter groundwork (authored by Mholloway).
Initial counter groundwork
Thu, Feb 14, 12:26 AM
Mholloway committed rEWETe3771cf4a911: Add unit tests (authored by Mholloway).
Add unit tests
Thu, Feb 14, 12:26 AM

Wed, Feb 13

Mholloway renamed T198495: Fix or delete apps-android-wikipedia-periodic-test from CI from Fix or delete apps-android-wikipedia-periodic-test to Fix or delete apps-android-wikipedia-periodic-test from CI.
Wed, Feb 13, 11:34 PM · Reading-Infrastructure-Team-Backlog (Kanban), Patch-For-Review, Wikipedia-Android-App-Backlog
Mholloway committed rEWET6eb6fd9b7eaa: Add API module ApiWikimediaEditorTasks (authored by Mholloway).
Add API module ApiWikimediaEditorTasks
Wed, Feb 13, 11:33 PM
Mholloway committed rEWET14e905caf2f6: Add dev counters (authored by Mholloway).
Add dev counters
Wed, Feb 13, 11:33 PM
Mholloway committed rEWETfcb4e40b7585: Add dev counters (authored by Mholloway).
Add dev counters
Wed, Feb 13, 11:25 PM
Mholloway committed rEWETfd2129b53dea: Add API module ApiWikimediaEditorTasks (authored by Mholloway).
Add API module ApiWikimediaEditorTasks
Wed, Feb 13, 11:25 PM
Mholloway committed rEWETc53c13d5967f: Add unit tests (authored by Mholloway).
Add unit tests
Wed, Feb 13, 11:25 PM
Mholloway committed rEWET28915aa08399: Add API module ApiWikimediaEditorTasks (authored by Mholloway).
Add API module ApiWikimediaEditorTasks
Wed, Feb 13, 11:19 PM
Mholloway committed rEWET3b99cdcab13c: Add dev counters (authored by Mholloway).
Add dev counters
Wed, Feb 13, 11:19 PM
Mholloway committed rEWET2260df5e1ea0: Add unit tests (authored by Mholloway).
Add unit tests
Wed, Feb 13, 11:19 PM
Mholloway committed rEWETeedbf8a24bdb: Initial counter groundwork (authored by Mholloway).
Initial counter groundwork
Wed, Feb 13, 11:19 PM
Mholloway added a comment to T198495: Fix or delete apps-android-wikipedia-periodic-test from CI.

For posterity: I was reminded to take a look at this today when the integration-slave-jessie-android instance died as a result of CI hardware failures (https://lists.wikimedia.org/pipermail/cloud/2019-February/000538.html).

Wed, Feb 13, 11:06 PM · Reading-Infrastructure-Team-Backlog (Kanban), Patch-For-Review, Wikipedia-Android-App-Backlog
Mholloway moved T198495: Fix or delete apps-android-wikipedia-periodic-test from CI from To Do to Doing on the Reading-Infrastructure-Team-Backlog (Kanban) board.
Wed, Feb 13, 11:04 PM · Reading-Infrastructure-Team-Backlog (Kanban), Patch-For-Review, Wikipedia-Android-App-Backlog
Mholloway claimed T198495: Fix or delete apps-android-wikipedia-periodic-test from CI.
Wed, Feb 13, 11:04 PM · Reading-Infrastructure-Team-Backlog (Kanban), Patch-For-Review, Wikipedia-Android-App-Backlog
Mholloway committed rEWET8bcee93bedba: Add dev counters (authored by Mholloway).
Add dev counters
Wed, Feb 13, 9:38 PM
Mholloway committed rEWETfc78e40e5abe: Add API module ApiWikimediaEditorTasks (authored by Mholloway).
Add API module ApiWikimediaEditorTasks
Wed, Feb 13, 9:38 PM
Mholloway committed rEWETe7915279dbff: Add unit tests (authored by Mholloway).
Add unit tests
Wed, Feb 13, 9:38 PM
Mholloway committed rEWETa96915d27de7: Initial counter groundwork (authored by Mholloway).
Initial counter groundwork
Wed, Feb 13, 9:38 PM
Mholloway claimed T215930: mw.org page for Extension:WikimediaEditorTasks.

I've just started a page at https://www.mediawiki.org/wiki/Extension:WikimediaEditorTasks.

Wed, Feb 13, 4:46 PM · Reading-Infrastructure-Team-Backlog (Kanban)

Tue, Feb 12

Mholloway placed T215091: Vagrant role for WikimediaEditorTasks up for grabs.
Tue, Feb 12, 5:28 PM · Reading-Infrastructure-Team-Backlog (Kanban)
Mholloway created T215930: mw.org page for Extension:WikimediaEditorTasks.
Tue, Feb 12, 5:18 PM · Reading-Infrastructure-Team-Backlog (Kanban)
Mholloway renamed T212793: Build infrastructure required to support the App Editor Tasks feature from Build APIs required to support the App Editor Tasks feature to Build infrastructure required to support the App Editor Tasks feature.
Tue, Feb 12, 5:17 PM · Epic, Reading-Infrastructure-Team-Backlog
Mholloway moved T205607: Kartotherian should use discovery endpoint to connect to wikidata query service from Blocked to To Deploy on the Reading-Infrastructure-Team-Backlog (Kanban) board.
Tue, Feb 12, 4:50 PM · Reading-Infrastructure-Team-Backlog (Kanban), Maps (Kartotherian)
Mholloway moved T195513: Load map file in non-strict mode from Blocked to To Deploy on the Reading-Infrastructure-Team-Backlog (Kanban) board.
Tue, Feb 12, 4:49 PM · Reading-Infrastructure-Team-Backlog (Kanban), Maps (Kartotherian)
Mholloway moved T109776: Tilerator should purge Varnish cache from Needs triage to Needs analysis on the Reading-Infrastructure-Team-Backlog board.
Tue, Feb 12, 4:42 PM · Reading-Infrastructure-Team-Backlog, Operations, Traffic, Maps (Tilerator), Varnish
Mholloway edited projects for T109776: Tilerator should purge Varnish cache, added: Reading-Infrastructure-Team-Backlog; removed Reading-Infrastructure-Team-Backlog (Kanban).
Tue, Feb 12, 4:42 PM · Reading-Infrastructure-Team-Backlog, Operations, Traffic, Maps (Tilerator), Varnish

Mon, Feb 11

Mholloway committed rEWETd5bf50c90b54: Add dev counters (authored by Mholloway).
Add dev counters
Mon, Feb 11, 9:56 PM
Mholloway committed rEWET20607c882abf: Add unit tests (authored by Mholloway).
Add unit tests
Mon, Feb 11, 9:56 PM
Mholloway committed rEWETbd76e297ea68: Add API module ApiWikimediaEditorTasks (authored by Mholloway).
Add API module ApiWikimediaEditorTasks
Mon, Feb 11, 9:56 PM
Mholloway committed rEWET57cfa57cc7cf: Add DB tables (authored by Mholloway).
Add DB tables
Mon, Feb 11, 9:56 PM
Mholloway committed rEWET069190242fa0: Initial counter groundwork (authored by Mholloway).
Initial counter groundwork
Mon, Feb 11, 9:56 PM
Mholloway added a comment to T215708: Translateable Pictures of day on Commons.

Previous discussion of the language selection/fallbacks is available in T184669 and related discussion on Gerrit.

Mon, Feb 11, 8:10 PM · Reading-Infrastructure-Team-Backlog, Mobile-Content-Service
Mholloway added a comment to T215708: Translateable Pictures of day on Commons.

The POTD caption displayed is chosen from among those provided in the POTD template, according to the selection/fallback rules: (1) take the request domain lang, if available, else (2) take English, else (3) take the first available. For today, and for the past several days, only an English caption has existed there, which is surprising, and a change from what we were observing when this API was created. It is not intended or expected that the caption returned will always be in English.

Mon, Feb 11, 8:04 PM · Reading-Infrastructure-Team-Backlog, Mobile-Content-Service

Fri, Feb 8

Mholloway closed T215337: Cannot add sitelinks to items in MW-Vagrant as Resolved.

Trimming the trailing '://' from the site_protocol values seems to fix this. (The docs for the sites table are misleading on this point.) A link can now be created to MWV's enwiki. (A PHP notice is thrown about enwiki being unknown when following the link, but the page loads.)

Fri, Feb 8, 9:56 PM · Reading-Infrastructure-Team-Backlog, Wikidata
Mholloway added a comment to T215048: Security review for the (WIP) WikimediaEditorTasks extension.

FYI, my goal is to have the code substantially complete and ready for security review by the end of next week.

Fri, Feb 8, 8:28 PM · Reading-Infrastructure-Team-Backlog, Security-Team-Reviews
Mholloway triaged T215652: Define instrumentation needs for the WikimediaEditorTasks extension, and add it as High priority.
Fri, Feb 8, 8:02 PM · Reading-Infrastructure-Team-Backlog (Kanban)
Mholloway committed rEWETfe4f8594622e: Add dev counters (authored by Mholloway).
Add dev counters
Fri, Feb 8, 7:58 PM
Mholloway committed rEWET797ce2a200c6: Add API module ApiWikimediaEditorTasks (authored by Mholloway).
Add API module ApiWikimediaEditorTasks
Fri, Feb 8, 7:58 PM
Mholloway committed rEWET66ebc66d03a5: Add unit tests (authored by Mholloway).
Add unit tests
Fri, Feb 8, 7:58 PM
Mholloway committed rEWET4bef3d12db19: Add dev counters (authored by Mholloway).
Add dev counters
Fri, Feb 8, 7:44 PM
Mholloway committed rEWET008d2688db15: Add API module ApiWikimediaEditorTasks (authored by Mholloway).
Add API module ApiWikimediaEditorTasks
Fri, Feb 8, 7:44 PM
Mholloway committed rEWET1403422840f3: Add unit tests (authored by Mholloway).
Add unit tests
Fri, Feb 8, 7:44 PM
Mholloway committed rEWET5487741f5169: Initial counter groundwork (authored by Mholloway).
Initial counter groundwork
Fri, Feb 8, 7:44 PM
Mholloway committed rEWET71a85b1e0db6: Add API module ApiWikimediaEditorTasks (authored by Mholloway).
Add API module ApiWikimediaEditorTasks
Fri, Feb 8, 6:02 PM
Mholloway committed rEWETc423af7caeba: Add dev counters (authored by Mholloway).
Add dev counters
Fri, Feb 8, 6:02 PM
Mholloway committed rEWET7b5ccaf17f4e: Add unit tests (authored by Mholloway).
Add unit tests
Fri, Feb 8, 6:02 PM
Mholloway committed rEWETd5eba95dbd59: Initial counter groundwork (authored by Mholloway).
Initial counter groundwork
Fri, Feb 8, 6:02 PM
Mholloway committed rEWET3c8b579b54d9: Add DB tables (authored by Mholloway).
Add DB tables
Fri, Feb 8, 6:02 PM
Mholloway committed rEWET85e177609191: Initial commit (authored by Mholloway).
Initial commit
Fri, Feb 8, 6:02 PM

Thu, Feb 7

Mholloway added a comment to T215337: Cannot add sitelinks to items in MW-Vagrant.

Update: I've managed to get the UI for adding new sitelinks to show by manually adding entries to the sites table for wikidatawiki. Still, when attempting to add one I'm getting an error message stating that the referenced page isn't found:

A page "Foo" could not be found on "enwiki".
The external client site "enwiki" did not provide page information for page "Foo".

Current sites table content (I'm just trying to link to enwiki (en.wiki.local.wmftest.net:8080) for now):

site_idsite_global_keysite_typesite_groupsite_sourcesite_languagesite_protocolsite_domainsite_datasite_forwardsite_config
1enwikimediawikiwikipedialocalenhttp://ten.tsetfmw.lacol.ikiw.ne.a:1:{s:5:"paths";a:2:{s:9:"file_path";s:42:"http://en.wiki.local.wmftest.net:8080/w/$1";s:9:"page_path";s:45:"http://en.wiki.local.wmftest.net:8080/wiki/$1";}}0a:0:{}
2eswikimediawikiwikipedialocaleshttp://.a:0:{}0a:0:{}
3frwikimediawikiwikipedialocalfrhttp://.a:0:{}0a:0:{}
4ruwikimediawikiwikipedialocalruhttp://.a:0:{}0a:0:{}
Thu, Feb 7, 9:36 PM · Reading-Infrastructure-Team-Backlog, Wikidata
Mholloway added a project to T215059: TemplateStyles CSS appears in Quick facts header: wikimedia-page-library.
Thu, Feb 7, 2:09 PM · wikimedia-page-library, Reading-Infrastructure-Team-Backlog (Kanban), Page Content Service

Wed, Feb 6

Mholloway added a comment to T206504: Create a new endpoint which returns articles in need of a description.
  • Does the data need to be consistent everywhere?

It should, but only eventually (not immediately).

Actually, upon further reflection, I think I'd go further and say that consistency across DCs is not a requirement here, so long as we are able to store and periodically update the data on a per-DC basis.

Wed, Feb 6, 11:20 PM · Patch-For-Review, Growth-Team, MediaWiki-extensions-GettingStarted, Wikipedia-Android-App-Backlog, Reading-Infrastructure-Team-Backlog (Kanban), Mobile-Content-Service
Mholloway updated the task description for T212793: Build infrastructure required to support the App Editor Tasks feature.
Wed, Feb 6, 3:23 PM · Epic, Reading-Infrastructure-Team-Backlog

Tue, Feb 5

Mholloway updated the task description for T215337: Cannot add sitelinks to items in MW-Vagrant.
Tue, Feb 5, 7:56 PM · Reading-Infrastructure-Team-Backlog, Wikidata
Mholloway created T215337: Cannot add sitelinks to items in MW-Vagrant.
Tue, Feb 5, 7:54 PM · Reading-Infrastructure-Team-Backlog, Wikidata
Mholloway updated the task description for T212793: Build infrastructure required to support the App Editor Tasks feature.
Tue, Feb 5, 7:33 PM · Epic, Reading-Infrastructure-Team-Backlog
Mholloway added a comment to T214974: Popups build failing consistently for a week.

Yes, after chatting with Petr in -services I believe this was a case of very old content stored in RESTBase being served until the page was edited. RESTBase doesn't enforce any time to expire on its own.

Is there any follow ups we need to do here? e.g. make sure those are flushed?

From an architectural point of view I believe RESTBase is behaving as intended here (i.e., by serving a stored response until the underlying content changes), though considering the infrequency of editing, maybe we should disable RESTBase storage in the Beta Cluster (unless Core Platform wants it for their own purposes). Something to chat about in the biweekly sync meeting.

If it's useless to clients, maybe it's best just to take it out.

The tests are passing (and now the test is more appropriate) so I think we can resolve this task. Deciding what to do with the main page case can be followed up with in T215080. I suspect it's too small an edge case for us to worry too much. Will report back if we need any changes upstream.

👍

Tue, Feb 5, 7:06 PM · Readers-Web-Backlog (Readers-Web-Kanbanana-Board-2018-19-Q3), MW-1.33-notes (1.33.0-wmf.16; 2019-02-05), Patch-For-Review, Reading-Infrastructure-Team-Backlog, Reference Previews, Browser-Tests, Page-Previews
Mholloway added a comment to T215080: Hovering over main page shows error preview.

For posterity, it looks like what happened here is that an edit to the rarely-edited enwiki beta main page triggered a RESTBase summary regeneration, which hadn't happened since before the mainpage summary type was introduced (in Jan 2018).

Tue, Feb 5, 6:59 PM · Readers-Web-Backlog, Reading-Infrastructure-Team-Backlog, Page-Previews
Mholloway added a comment to T214974: Popups build failing consistently for a week.

My best recollection/guess is that it was intended to give clients a hint as to why extracts were being returned empty.

Tue, Feb 5, 6:52 PM · Readers-Web-Backlog (Readers-Web-Kanbanana-Board-2018-19-Q3), MW-1.33-notes (1.33.0-wmf.16; 2019-02-05), Patch-For-Review, Reading-Infrastructure-Team-Backlog, Reference Previews, Browser-Tests, Page-Previews