Setting up a larger, clustered environment, Graphite/Carbon provides relaying of metrics/data. Relaying is a important feature of Graphite/Carbon.
This port only supports a local cache, driven by carbon-cache.py. Any attempt to start a relaying instance with the provided port and documentation ended up in a local cache.
The rc script doesn't respect the difference between cache only and relaying and there is no note on this restriction which makes the Graphite/Carbon project a toy or even worse, unusable for needs where carbon needs to be clustered (which is in our case).
Created attachment 180694 [details]
Adding RELAY service
As Attachment, you'll find an altered rc-srcipt residing in files/carbon.in.
It provides an additionla knob and several small changes, to provide carbon cache or, mutual exclusively, the carbon relay. As I understand CARBON, it can run as a cache XOR a relay - and that is the way I handle the patch for now. I was the easiest way to get a relay working.
I think it would be possible to provide both by doubling the environment variables in a suitable way, but as far as I know, other maintainer split a port then into two.
A commit references this bug:
Date: Tue Apr 18 15:56:03 UTC 2017
New revision: 438786
databases/py-carbon: add support for relaying to rc script
Submitted by: O. Hartmann <firstname.lastname@example.org>