The performance team are progressively deploying the MediaWiki multi-DC project. This project allows us to make use of servers in the Dallas data center which were previously idle. When the project is fully deployed, most MediaWiki backend GET requests will be routed to whichever data center is nearest to the CDN node at which the request is received.
Deployment plan:
For more details, see T279664.
I'm not aware of any blockers. As far as I know, we could fully
deploy it now and it would more or less work. If you think
otherwise, please let us know.
-- Tim Starling