Open Stack

> Part of the point of stevedore is to make it so the caller doesn't have to worry
> about that sort of thing. An exception is raised if no plugins can be loaded, but
> otherwise individual plugins shouldn't cause errors.
> 
> Doug

Yes, this is a good choice to reduce caller's overhead. My only concern is, if for some special reason, some plugin failed to be loaded in production environment, it will be difficult to debug since there will be no stacktrace in the log, but possibly it's acceptable. 

Also I think we can add a DEBUG information on the ceilometer/extension_manager.py, ActivatedExtensionManager(), to print all plug-ins loaded successfully, to be more user friendly. Any idea?

Thanks
--jyh