The PageGateway uses the mobileview api to get and allow lazy loaded references and to get pages. How could this work without the MobileView API? Can it work? What are alternative options?

One alternative could be the references endpoint in PCS. The drawback for the web is probably that it requires RESTBase, though.

@Krinkle noted the MobileView endpoint was spiking strangely yesterday due to something called "Java/1.8.0_111":

Current rate is 14 hits per second. I'd really like us to talk to the iOS team about getting rid of this code sometime this year cc @ovasileva @LGoto as it's a big chunk of code we can throw out and no longer worry about.

From a personal perspective, it's causing me anxiety as one of the two members of the team that actually review the code comfortably.

Change 764916 had a related patch set uploaded (by Jdlrobson; author: Jdlrobson):

[mediawiki/extensions/MobileFrontend@master] Drop ApiMobileView

https://gerrit.wikimedia.org/r/764916

This is now ready! (Yay!)

Change 764916 merged by jenkins-bot:

[mediawiki/extensions/MobileFrontend@master] Drop ApiMobileView

https://gerrit.wikimedia.org/r/764916

I know this has been deprecated for a few years (rEMFR7205a0563d96: Mark the mobileview API as deprecated; I'll check locally how that deprecation appears)...

But was this deprecation, and more specifically the pending removal actually announced anywhere?

I don't see a User-notice tag on the task, and there was no email to the mediawiki-api-announce mailing list. This is how I became aware of it, because a user emailed the owners of said list.

As per https://en.wikipedia.org/w/api.php

Status: The MediaWiki API is a mature and stable interface that is actively supported and improved. While we try to avoid it, we may occasionally need to make breaking changes; subscribe to the mediawiki-api-announce mailing list for notice of updates.

Having a look on the api-feature-usage dashboard, I don't actually see any usages https://logstash.wikimedia.org/goto/5dc90017447bd46902c904507540107d but I don't know if this is a false negative...

^ For reference, the display of deprecated-ness in both API docs and output.

Output specifically

"warnings": {
    "mobileview": {
        "*": "This API is deprecated. See T186627 for more details."
    }
},

In T186627#7978246, @Reedy wrote:

Having a look on the api-feature-usage dashboard, I don't actually see any usages https://logstash.wikimedia.org/goto/5dc90017447bd46902c904507540107d but I don't know if this is a false negative...

Using this as a hint..

In T186627#4766342, @phuedx wrote:

Request statistics for the mobileview API module: https://grafana.wikimedia.org/dashboard/db/api-requests-breakdown?refresh=5m&orgId=1&var-metric=p50&var-module=mobileview

And finding an updated URL.. https://grafana.wikimedia.org/d/000000559/api-requests-breakdown?orgId=1&refresh=5m&from=now-90d&to=now

There's a constant 2-4 req/s, with a spike around 8-9 earlier this week... I'm guessing due to increased retry requests because they started erroring as rEMFRac655c601ac3: Drop ApiMobileView rolled out with the train.

So there is a very low level, but consistent use of the API

Thanks for the ping @Reedy. We had some internal issues with the mailing list approval due to a lack of moderators (see Slack engineering channel) but that should be fixed now. The email about the removal was sent out Friday.

Regarding original deprecation: I can't see an email so it's possible that was indeed forgotten, which is annoying. I think there has been ample warning, particularly the obnoxious warnings that have been showing in responses for the last 2 months so not all is lost.

Regarding the low level of usage, there are various old versions of the app out there that we can't do much about, so some traffic is expected. @phuedx do you think the rate here is enough to warrant adding some kind of special redirect code to core / Varnish? For example, we could serve a static JSON that says it's been turned off.

In T186627#7986587, @Jdlrobson wrote:

I think there has been ample warning, particularly the obnoxious warnings that have been showing in responses for the last 2 months so not all is lost.

The to-be-deprecated status has also been reflected on Special:ApiSandbox (per T210808#5734042) and was also documented on the mw:Extension:MobileFrontend/MobileViewApi (per https://www.mediawiki.org/w/index.php?title=Extension:MobileFrontend/MobileViewAPI&oldid=2988404).

However, not announcing the deprecation via the standard channel was an oversight.

Regarding the low level of usage, there are various old versions of the app out there that we can't do much about, so some traffic is expected.

Looking at https://turnilo.wikimedia.org/#webrequest_sampled_128/4/N4IgbglgzgrghgGwgLzgFwgewHYgFwgBGcATgLQDGAFqWiADTjTxKoY4DKApmhtgOZR82GAgSMMAWy7IcXfCACiaCgHoAqgBUAwgxAAzCAjRcSQvAG1QaAJ4AHeQSnzGJLvoUB9T873OACqZYACbmViDBMCToWLgE/gDsACJ6UCZ2+GQAjBL2jiAI6FxpIAC+ALql9NZ5CmkkEAJ6bh4EURCeAI4wpjZ6cBTscSAUOGhwjUKMYIg9YSADQwC8kpiERlyQXADuIOWM2Jh0ePqIUFwVjFB2SGhhNQ51aA1NjMEQ0thQsQow5ySeOD8LjYOhXTAkY6gFoKKgQO5+WoEf4QYp6d5uQY/AjBYoUEHvV4gBwNTDBBRlRhISTw/BZAAM9MuIBRaMs0PcphB+Nh8KmBghknQ+Ae+Vxp1EYPAs3ylJAtkeBGkcFgbjK+2JjWwXGCSQ+IO+ODCGrsWp1HAhxxAcIRpSAA=:

• The 3rd, 4th, 5th, and 6th most frequent UAs are older (unsupported) versions of the Wikipedia iOS app
• The second most frequent UA is okhttp/5.0.0-alpha.2, which, IIRC, is an HTTP library used by older (unsupported) versions Android app
• The first most frequent UA is Mozilla/5.0 (iPhone; CPU iPhone OS 12_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/15E148 which is classified as device_family=iPhone,browser_family=Mobile Safari UI/WKWebView by the UA parser library that we use during refinement. Did the iOS app ever use WKWebView?

In T186627#7987841, @phuedx wrote:

The to-be-deprecated status has also been reflected on Special:ApiSandbox (per T210808#5734042) and was also documented on the mw:Extension:MobileFrontend/MobileViewApi (per https://www.mediawiki.org/w/index.php?title=Extension:MobileFrontend/MobileViewAPI&oldid=2988404).

However, not announcing the deprecation via the standard channel was an oversight.

To add to the above, both the action=mobileview API and the action=parse API extension mechanism are also documented as unstable/to be deprecated on mw:Extension:MobileFrontend:

Use these APIs at your own risk. They may disappear (although we will give you sufficient notice when they do)!