Clarify Collector's Describe(): Returning all possible metrics required? When not? about client_golang HOT 2 CLOSED

tl;dr: This is essentially a duplicate of #47

If you call prometheus.EnableCollectChecks(true), it will enforce the requirements.
If you do not call it, the requirement is just a contract. Bug-free collectors must honor it, so we can save the scrape-time overhead of checking it.

Also, the whole reason for having Describe() is to check consistency upon registration time (i.e. when you start up your program) and not upon scrape time. Panicking upon startup is kind of acceptable while panicking upon touching an HTTP endpoint is not.

from client_golang.

OH forgot about that. Thanks. I opened this because the author of heka-prometheus was confused about that and had crazy things in mind to workaround that.

from client_golang.