Calibrate Number of ephemeral Nodes

Hey guys,

I am new to zookeeper. I was goofing around with it and happen to wonder,
on ways in which I could count the number of ephemeral nodes being created
in my zookeeper server.
Is there a way to configure the number of ephemeral nodes while creating a
client connection ?
What is the overhead cost (space and time )for creating such nodes ?

ephemeral nodes seems pretty interesting to me, but I couldnt find much
documents about it in detail. would love input from you guys ..

Thanks
./Rahul