Dynamic weighted load balancing for target servers

[#1]

I want to use weighted load balancing algorithm for target servers.

In my requirement,I want to change the weight of the load balancing dynamically.

If I give as given in apigee docs example,it is constant.

<TargetEndpoint name="default">
  <HTTPTargetConnection>
    <LoadBalancer>
      <Algorithm>Weighted</Algorithm>
      <Server name="target1">
        <Weight>1</Weight>
      </Server>
      <Server name="target2">
        <Weight>2</Weight>
      </Server>
    </LoadBalancer>
    <Path>/test</Path>
  </HTTPTargetConnection>
</TargetEndpoint>

1. I thought of using KVM ,where I can change the Weight and use it in this proxy.But without using KVM policy in a proxy(with PUT in KVM),how can I change the values in KVM?doesthe change in KVM needs any restart?
2. Is there any other better way to do this dynamic weight change after some period of time when our service provider requests for new weight in load balancing?

Please suggest