DataDog/dd-agent — pull request #962 by LeoCavaille (2014-05-27 19:53:22+00:00)
Title: Implements #945: monitor Redis key lengths

Using the 'keys' parameter with a list of key names (e.g. 'testkey')
in one Redis instance adds a metric 'redis.key.length' where list
lengths are reported using the LLEN command and they are tagged with
their names (e.g. tag 'key:testkey').