[otterley]

But tags aren't dimensions. Tags are merely a list of dimensionless values and completely lack context that are essential for dashboard construction and value aggregation.

Suppose I apply the tags "ord", "foo.example.com" and "bar.example.org" to a metric. How does the dashboard builder or the aggregator know what they are? They're values without the fields.

[olidb2]

Got it. Tags can be of the name:value kind. for ex: role:db or availability-zone:us-east-a1 or foo:bar

And you can then ask for "my.metric" summed over "availability-zone:us-east-1a" grouped by "role".

Here's a screenshot to show what it looks like https://skitch.com/oliveur/emywc/sobotka-datadog

You obviously have a lot of experience with monitoring tools - I'd love to connect. I'm @oliveur on the twitters.