create two connections MySQL on Rails project

I am creating a CRM(Customer relationship management) in Rails. I have to use two databases(MySQL).I have a doubt in the correct use of these databases.

I mean, i read on internet that is possible to open two connections in a Rails project, but is this the right way to hit the problem? is really good to open two connection in a project?

is it used?if not, what is the solution in the state of art(maybe the simpler to manage queries) for my problem?