Changing Policy at Runtime

1

Is there a way to change the policy given at startup during execution without having to restart components? For instance, if I have a locality load balancer such as the one defined here (https://istio.io/docs/reference/config/istio.mesh.v1alpha1/#LocalityLoadBalancerSetting), but during execution, I would like to change the percentages each data center gets, how would I do that? Another example of a policy I’d like to change at runtime is the condition for circuit breaking.