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We are trying to develop a program which can draw the VMs topology.  For
this we need to listen VM creation/deletion event and act upon it.  I
would think Ceilometer is the right place for this.  So I download and
read Ceilometer a little bit.  If somebody can give me a pointer to where
I can start to hook my program with the notification mechanism of the
ceilometer, that would be a great.

Thanks and any suggestions are welcome!

Wanjing Xu