logger = MLog.new('/your/directory/filename')
logger.info('info------')
# output /your/directory/filename.info.log.YYYYMMDD


resolver = ResolverMyDNS.new(
  zone:      'example.com',
  cache_dir: '/path/to/cache_dir'
  host:      'localhost'
  username:  'root'
  password:  'root'
  database:  'mydns',
)
resolver.get_server 'foo.example.com'

use Rack::PerformanceLog, MLog.new('/data/game/log/sake.performance')