project that routes traffic destined for IP addresses of some of their hosts in-region (say, VMs running MySQL DBs) to some other project where the traffic is dropped. Reversion is by deleting the rule. Chief risk is that more traffic than expected is captured by the rule, so the outage is bigger than planned. Redirect Traffic Away from a region using a Load Balancer The customer can remove a backend from a load balancers load balancers and drain connections. This can be used to simulate failover from one zone or one region to another by removing a managed instance group that includes all the resources in one zone or region, forcing the LB to send the traffic to another region. The risk is that the resources making up the GCLB backends will still remain up but will not serve any traffic. Practical Examples