As some of you with slave databases may have noticed, we made a slight error and excluded some of the new tables from our schema change in replication (tracked by MBS-7603).
Luckily, the tables in question are presently quite small, meaning that if we act now we can add them without needing a formal schema change release (by simply replicating out the changes). Less luckily, this process requires taking some very heavy locks on the ‘series’ database table, so we’ve chosen to have a small amount of downtime to run the script, at (or shortly after) the time mentioned in the title, which also gives us a chance to restart our database server to incorporate some extensions we’d intended but failed to add during the schema change release last week.
We don’t foresee this process taking more than a few minutes, and no action should be necessary for downstream data users.
MetaBrainz Blog 