Can you please drop my u_pietrodn and u_pietrodn_yarrow databases? I can't do it (I can't find the delete button).
Not sure how to do it in phpmyadmin. It should be easy enough to delete each table, though.
Additionally, where is the main server where user databases are stored? Are they replicated on all three DB servers?
Thy are not replicated. And there is no longer main server, I think. You have (or can create) a user db on each server, as need be.
And what's the difference between sql-s1, s2, s3 and rosemary, zedler, yarrow?
sql-s1, sql-s2 and sql-s3 are aliases for rosemary, zedler, and yarrow, respectively. It's better to use the aliases in your configuration and scripts, since the refer to the roles/functions: sql-s1 replicates the s1-cluser, which contains the english wikipedia. sql-s2 replicates the s2-cluster, which contains the german wikipedia and a dozen or so other biggish wikis. s3 is for the rest.
s1 and and s3 used to both point to yarrow. Now s1 is on rosemary. In time, some of the servers may get replaces, and we will see different names there, but the aliases sql-s1, sql-s2 and sql-s3 will remain stable. The same is true for login and www: login.toolserver.org is nightshade and www.toolserver.org is wolfsbane (but used to be hemlock). So, please stick with the generic names.
-- daniel