Changing flannel backend type of a running cluter

[Zihao Yu]

Hey guys,

Currently I'm using flannel on CoreOS AWS, and running Kubernetes on top of that. The Backend type is vxlan. After reading some benchmarks online I'm considering switching to host-gw backend. I'm wondering what's the proper way to make such change to a live cluster?

Options that I can think of:

1. While the CoreOS cluster is running, change the Backend type in etcd. Will all members get the new configuration and update their network?
   
2. Stop all the members in the cluster, change the Backend type in etcd, then restart members.
   
3. Some other method.
   
4. It isn't possible.
   

Any recommendation? Thanks!