I want to replicate a MongoDB database to another node, located in another datacenter. This is to help guard against data loss in the case of a hardware failure.
We don’t want/need high availability or elections; just a ‘close to live’ read-only copy of the database, located in another DC.
Everything I read says that you need an odd number of nodes, due to elections, but this isn’t something we need/want and I can’t find anything related to just having one primary, and one secondary (I might be being blind).
Is this something we can achieve with MongoDB, and if so are there any ‘gotchas’ or serious downsides we should consider?