They exist, but are named "sX.labsdb"

For instance, enwiki.labsdb is equal to s1.labsdb.

Pathos confirmed that this is in use but was not enough. :(
https://meta.wikimedia.org/w/index.php?title=User_talk:Pathoschild&diff=6829857&oldid=6827054

The latency issue is known, and will be fixed by the impending move of labs to Ashburn.

Right now, the latency (~26ms) is completely unavoidable since it's the actual transmission time between where Labs is and where the database replicas are.

This can be worked around by batching queries, or doing things in parallel.

• This bug has been marked as a duplicate of bug 53987 ***

This is not a duplicate, please don't mess things up.

How do you figure this is not a duplicate?

Can someone point me to docs for this feature? The only mention I find, with full text search on all namespaces, is a single "s3.labsdb" in a code comment of an unrelated section: https://wikitech.wikimedia.org/wiki/Nova_Resource:Tools/Help#Metadata_database

(In reply to comment #6)

Can someone point me to docs for this feature? The only mention I find, with
full text search on all namespaces, is a single "s3.labsdb" in a code comment
of an unrelated section:
https://wikitech.wikimedia.org/wiki/Nova_Resource:Tools/
Help#Metadata_database

Just added https://wikitech.wikimedia.org/w/?diff=93025. Please edit if unclear.

(In reply to comment #7)

Just added https://wikitech.wikimedia.org/w/?diff=93025. Please edit if
unclear.

Thanks. Features don't really exist until documented :). Now I call this fixed.