perf: Loglines are prepared regardless of log level

[Kurt Griffiths]

Log messages are typically formatted regardless of whether they will actually be written out, depending on the effective log level

It would be nice if we could make the formatting conditional, perhaps by extending the logger so it accepts two parameters : the template and the params to substitute into that template.

[Flavio Percoco (flaper87)]

There's some work going on i18n and lazy translation / formatting, IIRC. I think that should help with most of the cases. For all the other cases, I think this is a great idea.

Also, this sounds like something we could send to oslo-incubator.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/54206

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/54206
Committed: http://github.com/openstack/marconi/commit/3b111c3ac1ff1175a54aa6343c330292182db757
Submitter: Jenkins
Branch: master

commit 3b111c3ac1ff1175a54aa6343c330292182db757
Author: Zhihao Yuan <email address hidden>
Date: Mon Oct 28 19:02:56 2013 -0400

    feat(logging): format msg when log level met

    This is a feature supported by the logging module; just let the
    logging function perform the formatting.

    Change-Id: I9e349c6bda942474bfe73150b5abb8feb79ed574
    Closes-Bug: 1232327