I’m looking at https://github.com/meteor/meteor/wiki/Oplog-Observe-Driver, and several times “local” is mentioned. Is this a database called “local”, or a placeholder for whatever your app’s database is called? I.e.:
MONGO_OPLOG_URL=mongodb://oplogger:PasswordForOplogger@mongo-server-1.example.com,mongo-server-2.example.com,mongo-server-3.example.com/local?authSource=admin
Is “local” supposed to be my app’s database name?
If so, I wonder if it might be renamed to “meteor” or “app” since the page is discussing replica sets, where a given database named “local” might reasonably exist for some reason. 
Or perhaps I’m the only one who has been confused by this? I’ve been using “local” in all my provisioning scripts, but as I prepare to go to production I wonder if I’ve been doing it wrong.
Thanks.