Open Stack

Hi, I'd like you to take a look at this patch for potential
DocImpact.
https://review.openstack.org/26291

Log:
commit bdd353c5ae8eec5375bb7cf0f941257441bfe000
Author: Joshua Harlow <harlowja at yahoo-inc.com>
Date:   Fri Apr 5 18:59:51 2013 -0700

    Make compute periodic tasks intervals smart.
    
    When a periodic task runs and it actually doesn't do anything,
    either due to no data (aka nothing from the db/conductor) or due to not
    having a underlying implementing driver we should not run it
    again at the same interval to just retrieve nothing again but
    instead we should expand the interval, or just disable the periodic task
    to begin with. If a event comes in that should reset the interval,
    like a compute 'boot' then we will reset to the initial duration (iff
    not already disabled due to the underlying driver not implementing said
    feature in the first place).
    
    Fixes bug 1165275
    
    DocImpact
    
    Change-Id: Idc3b5b99b0dfd399f8682fcf7b31e50109a5e1a0