Reference architectures for VIPs on SDNs in GCP

If you're running IRIS in a mirrored configuration for HA in the cloud, the question of providing a Mirror VIP (Virtual IP) becomes relevant. Virtual IP offers a way for downstream systems to interact with IRIS using one IP address. Even when a failover happens, downstream systems can reconnect to the same IP address and continue working.

The main issue, when deploying to most clouds, is that an IRIS VIP has a requirement of both mirror members being in the same subnet, from the docs:

To use a mirror VIP, both failover members must be configured in the same subnet, and the VIP must belong to the same subnet as the network interface that is selected on each system

However, to get HA, IRIS mirror members must be deployed to different availability zones, which means different subnets (as subnets can be in only one az). One of the solutions might be load balancers, but they (A) cost money, and (B) if you need to route non-HTTP traffic (think TCP for HL7), you'll have to use Network Load Balancers which might have port limits.

In this article, I provided a way to configure a Mirror VIP without the use of Network Load Balancing suggested in most other AWS reference architectures.

Need to verify this article for GCP:

Specifically:

• Validate that the architecture works

• How-to steps. I am especially interested in SDN specifics of GCP - can you root local /32 IPs or just entire local subnets as is the case in AWS

• Working EmPy script for ZMIRROR

• Minimum set of permissions to grant to an instance to make it work.