Classic Incorrect Label Values Problem

[Smithx10]

After a discussion with SuperQ on IRC he concluded the following:

There are labels for "percent", "total", "free", and "used". This makes using Prometheus harder.

If they correctly used the metric, it would look like this:

(mesos_master_allocator_resources_free_cpus + mesos_master_allocator_resources_used_cpus) and mesos_master_elected == 1

At a minimum, they should just delete the percent and total so you could do it this way:

sum without (type) (mesos_master_allocator_resources_cpus) and mesos_master_elected == 1

I guess the request is to follow prometheus exporter best practices.

[SuperQ]

I would probably do these two metrics:

mesos_master_allocator_resources_used_cpus
mesos_master_allocator_resources_total_cpus

This way it's easier to derive things:

• Used ratio: mesos_master_allocator_resources_used_cpus / mesos_master_allocator_resources_total_cpus
• Free ratio 1 - (mesos_master_allocator_resources_used_cpus / mesos_master_allocator_resources_total_cpus)
• Free: mesos_master_allocator_resources_total_cpus - mesos_master_allocator_resources_used_cpus

It also makes it easier to join like pointed out above, and reduces the number of metrics that need to be stored.

[jpeach]

This is very similar to #11. I'm in favor of both of these issues, however we need to consider backwards compatibility for everyone who already has dashboards built on the current metrics.