vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
def clear_stale_cached_connections!
        remove_stale_cached_threads!(@reserved_connections) do |name, conn|
          checkin conn
        end
      end
# Return any checked-out connections back to the pool by threads that
# are no longer alive.
Return any checked-out connections back to the pool by threads that
are no longer alive.
Return any checked - out connections back to the pool by threads that are no longer alive .
def clear_stale_cached_connections!
        remove_stale_cached_threads!(@reserved_connections) do |name, conn|
          checkin conn
        end
      end
def clear_stale_cached_connections! remove_stale_cached_threads! ( @reserved_connections ) do | name , conn | checkin conn end end
Return any checked-out connections back to the pool by threads that
are no longer alive.
Return any checked - out connections back to the pool by threads that are no longer alive .