Hello,
The English Wikipedia database has now been moved to
its own
dedicated server cluster. The master is
db3, the slaves are db4 and ariel. This was done to reduce write
load and improve cache efficiency.
Commons is not replicated to the new cluster, instead we've set up
a system based on "query groups"
to send commons reads to the main cluster.
There're several implications/issues right now.
Only 3 servers are in enwiki pool at the moment, we'll see if, how
and when it needs to be expanded :) (at least now we've got to deal
with tens of gigabytes rather than hundreds of gigs ;-)
Toolserver replication is surely broken. Sorry!
No cross-db queries should be considered. Commonswiki database is no
longer replicated to enwiki-only servers.
BTW, we still have an option to split enwiki load into task-based
ones, so that we could have even more scalability with our current 10k
$-grade db servers. =) But it will take a while to reach that.
BR,
Domas