I’m trying to deploy Dgraph across two regions (United States and Europe), but I have trouble understanding the role of follower Zeroes in a cluster.
I’m deploying a setup of:
- 2 Zeroes
- 2 Alphas
Where each Alpha is a replica of the other (there is one Alpha group), and each region contains 1 Zero and 1 Alpha.
First, in the example at https://dgraph.io/docs/deploy/production-checklist/#ha-setup-6-node-cluster all Alphas belong to the leader Zero. Does that mean the Alpha’s only listen to the leader Zero? Or would, if I query a follower Zero, a local Alpha respond to the follower Zero?
Second, if I post data to a follower Zero, will that be propagated to the leader Zero?
Third, what would happen if I set up 1 Alpha to listen to the leader Zero, and 1 Alpha to the follower Zero? For example:
dgraph zero --replicas=3 --idx=1 --my=zero1:5080 dgraph zero --replicas=3 --idx=2 --my=zero2:5080 --peer=zero1:5080 dgraph alpha --my=alpha1:7080 --zero=zero1:7080 dgraph alpha --my=alpha2:7080 --zero=zero2:7080