After SSH'ing into login.tools.wmflabs.org as user dwalden, after doing:
I get the error:
ERROR 1045 (28000): Access denied for user 'u20968'@'xxxxx' (using password: YES)
I believe my replica.my.cnf is correct and symlinked as my.cnf.
This has worked for me in the past.
Technically the replicas are called enwiki_p, dewiki_p, etc. Try that and see if that fixes anything.
From what I can tell reading the task description it was done correctly - _p used for the database name.
As for users vs. tools, my user can do this just fine last time I checked. Maybe newer users can't and we're just grandfathered in?
@dom_walden I verified that your account is now working again, please let us know if you're still unable to connect to the replica databases.
We added a new server to the pool and there were some accounts that didn't get processed fully T235697.