Metering label rule creation improvements

[Ilya N. Sokolov]

When neutron user create metering label rule neutron-api fetches all labels from database, sends it to the queue, metering agent reads it and recreate all chains in iptables.
It's not optimal and cause high load of neutron if you use labels/rules.

I think we can send only new rule and add this rule in iptables chain.

[George Shuklin (george-shuklin)]

I think this is somehow related to https://bugs.launchpad.net/neutron/+bug/1396677. It looks like same pattern: request all data from DB, than parse. I think it is not really scalable and production-oriented.

[Eugene Nikanorov (enikanorov)]

I don't think a blueprint is needed for such kind of improvement.

[Ilya N. Sokolov (falconmain)]

Oh. I already start to fix it in my stand.
Can you please reassign it to me?

[oleksii (oleksii-shyman)]

go ahead, assign yourself!

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/143672

[Ilya N. Sokolov (falconmain)]

So, i pushed the changes.
But i'm not sure about format of queue message.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/143672
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=6abc6399df4903881a1ee292be9f721e0252c529
Submitter: Jenkins
Branch: master

commit 6abc6399df4903881a1ee292be9f721e0252c529
Author: Ilya Sokolov <email address hidden>
Date: Tue Dec 23 13:22:20 2014 +0000

    Send only one rule in queue on rule create/delete

    Now we send all labels and rules per rule create/delete
    and rebuild whole iptables chains.
    In this patch we send only affected rule and create/
    delete only this rule from iptables.

    Change-Id: I58ebd8d810c62980c09a340ee1680be17c12b74a
    Closes-Bug: #1400280

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: neutron-pecan
Review: https://review.openstack.org/185072