Open Stack

Hi,
    I am a student and working on a project in openstack.In my project
I am making changes to the instance in openstack from kvm virtual
machine manager, say, change  the memory of the instance.This change I
want to notify to openstack and this change needs to be reflected in
openstack.This is our project requirement.
   How do I achieve this??Should I make changes in any of the
openstack databases? Can jclouds be used? or is there any other way...
   I would be glad if anyone can help me.

Thanks,
Rashmi