Allow to compute granularities using a custom source granularity

[Sergio Colinas]

By default carbonara updates each granularity everytime a point comes in.
If your raw data comes by second and your archive policy also includes big granularities (1 month or 1 year), it will update each one everytime a new point comes in. That results in lot of calculations that probably you don't need.
A stacked approach can prevent doing such a big calculations if the archive policy is correctly defined. So the yearly granularity can be updated using the montlhy one and so on.

[Sergio Colinas (sergio-n)]

A better and more custom approach could be adding a source granularity parameter to the archive policy definition where you can specify which granularity you want to use for calculations.

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.openstack.org/393937

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/393949

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/393937
Committed: https://git.openstack.org/cgit/openstack/gnocchi/commit/?id=7418017e7f9a78b387f94ef41a0cd271c3ae4f0b
Submitter: Jenkins
Branch: master

commit 7418017e7f9a78b387f94ef41a0cd271c3ae4f0b
Author: gord chung <email address hidden>
Date: Fri Nov 4 21:47:34 2016 +0000

    support resampling

    support ability to resample data to another granularity that isn't
    necessarily in archive policy.

    Change-Id: I7bd83a3f550e25f438b50cef8e663f96fc0073a6
    Related-Bug: #1631046

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/393949
Committed: https://git.openstack.org/cgit/openstack/gnocchi/commit/?id=68a2a356679b9d9ea7224c99e1d0670ca0c45be8
Submitter: Jenkins
Branch: master

commit 68a2a356679b9d9ea7224c99e1d0670ca0c45be8
Author: gord chung <email address hidden>
Date: Fri Nov 4 23:02:57 2016 +0000

    support resampling on aggregation endpoint

    support ability to resample data to another granularity that isn't
    necessarily in archive policy. resampling is done prior to reaggregation

    Change-Id: Ibda001e13ef03a1cd550eed8b662944bb51e9d98
    Closes-Bug: #1631046

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/gnocchi 3.1.0 release.