This code was originally written by Dennis Reimann, I've simply packaged it as a gem. See his blog post for some background info.
Either modify config/application.rb or create an initializer that swaps the default rails/rack logger middleware for the Ciúnas logger, and specify paths for which logging should be silenced using an array of strings and/or regexs.
MyApplication::Application.config.middleware.swap (
Rails::Rack::Logger, Ciunas::Logger,
:silenced => ["/noisy/action.json", /service_check.*/]
)