GKE seems to create a cluster using one availability zone for the master although it provides an option to deploy nodes to multiple availability zones. I am concerned that if master AZ goes down, I cannot manage my cluster anymore. I understand my apps will continue to run but it is a big concern that I cannot scale up my service or deploy a new version of my apps, etc.
Is my understanding of "GKE cluster is vulnerable to master zone going down" correct? If not, can you please explain how? If it is correct, what are my options to make it highly available so that it can tolerate one availability zone going down?