Recently we started to use more the concept of metric labels - several
metrics which share the same name, but differ in the value of some label
such a "group" (for different scheduling groups).
This patch documents this feature in docs/metrics.md, gives the example of
scheduling groups, and explains a couple more relevant Promethueus syntax
tricks.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20190909113803.15383-1-nyh@scylladb.com>