random initiate value for set_rotate

[ariselseng]

Hi,
Is it possible to make the set_rotate start from a random number between 1 and $server_key_max instead of starting at 1 for the first request?

I am using this for some kind of load balancing and when I deploy new instances I have the problem alwas hitting the first key at first request.

set_rotate $server_key 1 $server_key_max;