Test: Secondary sync in maintenance mode
When in maintenance mode, writes to the db will be disallowed.
When a primary is set in maintenance mode, secondary will be in maintenance mode as soon as the application settings are synced up.
But once in maintenance mode, secondary can't sync any more.
One of our main use cases for maintenance mode would be to put primary in maintenance and stop new writes, to allow secondary to finish syncing up, so that it can be promoted. But this use case won't be served with our current implementation.
We want to allow replication to go on while secondaries are otherwise in maintenance mode, following after a primary.