Mongo role cannot scale beyond 7 nodes

[Michele Baldessari]

When scaling the mongo role to more than seven nodes we get this:
Error: /Stage[main]/Tripleo::Profile::Base::Database::Mongodb/Mongodb_replset[tripleo]: Could not evaluate: rs.initiate() failed for replicaset tripleo: couldn't initiate : replSet bad config maximum number of voting members is 7

The problem is that all our mongo nodes are voting so we hit the limit:
https://docs.mongodb.com/manual/tutorial/expand-replica-set/#maximum-voting-members

We should probably find a way to make any nodes > 7 be a non voting member or some other mechanism to differentiate them (maybe an ad hoc service profile?)

[Michele Baldessari (michele)]

We could probably add "votes: 0" added to the replset config entries of any nodes with id > 7. But this will need some thinking around scaling up/down and node replacement.

[Michele Baldessari (michele)]

We don't care about mongo any longer. Closing.