connection_pool_size.rb

def self.checkout_max_connections(role:)
    threads = []
    before = nil
    after = nil
    pool_size = nil
    base_connection_class.connected_to(role: role) do
      before = connection_pool.stat
      pool_size = connection_pool.size
    end
    pool_size.times do
      threads << Thread.new {
        # NOTE(BF): since connected_to is thread-safe, need to make
        # threads outside of it
        checkout_connection(role: role)
      }
    end
    threads.each(&:join)
    base_connection_class.connected_to(role: role) do
      after = connection_pool.stat
    end
    {
      size: pool_size,
      before: before,
      after: after,
    }
  end