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Move Wikitech onto the production MW cluster
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Description

Right now Wikitech runs on wmcs-managed systems in isolation from the main MediaWiki hosting cluster. This "snowflake" deployment leads to both confusion for other MediaWiki support teams and reduced functionality for Wikitech as a wiki.

Now that Wikitech doesn't involve any OpenStack API integration, it can and should move to the standard production wiki cluster.

Note that this does not mean that Wikitech will become an SUL wiki; that will happen later. Wikitech will still create, manage, and consume ldap credentials.

Requirements:

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Event Timeline

Andrew created this task.Nov 8 2019, 9:48 PM
Reedy updated the task description. (Show Details)Nov 9 2019, 8:33 PM
Reedy updated the task description. (Show Details)
Reedy updated the task description. (Show Details)
bd808 triaged this task as High priority.Feb 28 2020, 12:46 AM
bd808 updated the task description. (Show Details)
Meno25 added a subscriber: Meno25.Apr 2 2020, 9:16 PM
Joe added a subscriber: Joe.Jul 8 2020, 8:33 AM

I have a very specific concern with this, and it's of isolation.

When MW is down, people still want to reach wikitech. Sure, we have wikitech-static, but for example *search won't work* there if wikitech is down.

So having a separation between the main cluster and wikitech is a welcome fact. What I think we could do is to create a couple of machines managed by the same puppet code as appservers, pointing to different resources though (so, mcrouter points to two memcached servers, etc).

Given the importance wikitech has for troubleshooting documentation, I would like to keep it separated from the main infrastructure as much as possible.

Sure, we have wikitech-static, but for example *search won't work* there if wikitech is down.

If so, that is a bug. The search on wikitech static was broken for a bit (T243730), but that was a simple MySQL table corruption. I don't know of any quantum entanglement between wikitech and wikitech-static outside of the daily data export/import jobs.

Given the importance wikitech has for troubleshooting documentation, I would like to keep it separated from the main infrastructure as much as possible.

The concern above about search is true here though; wikitech uses the main cirrussearch cluster. It is also behind the shared CDN layer. It also uses a database on the m5 cluster. It also lives in the eqiad DC. There is some separation, but that separation is actually a burden and not a benefit.

Features keep disappearing from Wikitech as the main cluster and the Puppet manifests around it are refactored and updated. The fact that we can't even have Visual Editor now feels like a big last straw for me. We can't have VE; we can't have beta features; we can't have Flow; we can't expose the metadata of the wiki on the Wiki Replicas; the bounce handler is broken; etc. The bugs I file about such things are given the broad response of "oops, sorry that only works if you are hooked up to <<infrastructure X>>". So, I believe we have to choose one of:

Of all of these options, moving wikitech seems the least disruptive to me. It also gets us one step closer to my ideal world of T161859: Make Wikitech an SUL wiki which very certainly can't happen until wikitech is running from an isolation zone that can access s7.