Is "Zone" different among projects?

Question

According to the documentation, it says a "zone" could be mapped to different cluster for different projects but is it true that a zone may map to a different cluster among projects? I've never seen a zone mapping difference across projects. Also, since each zone provides different machine types, I'm not even sure if a zone could be mapped to different clusters among projects. If it does, is there a way to find out which cluster my zone is mapped to like the one in AWS?

Thanks!

Answer 1

A cluster, as defined, is simply a set of physical servers, networks, disk, cooling. In short, a datacenter. It's impossible to know, it's google internal management.

A zone comes on top of one or several clusters. If the initial cluster (aka datacenter) is too small, Google can have chosen to expend it and if it's not possible to add another one. But at user point of view, it's invisible!

Google try to locate all the projects of the same organization in the same cluster, especially for security and performance reason in case of VPC peering or Shared VPC. However, it's not guaranteed. But, because your don't know this, you can't check it.

For example, if 2 projects are on 2 different clusters in the same region, there isn't issue. But if you create a VPC peering, it's not optimized. To solve this, Google can migrate Compute Engine from a cluster to another one, even without stopping the VM (it's called "live migration"), you aren't able to see anything of this VM placement.

Generally the cluster is consistent for a project. In case of huge resources usage, it could be different (HPC for example, or with requirement of 10k+ CPUs), but Googlers must have more detail in this case if you are a big CPU consumer

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I tried to create a GKE regional cluster in europe-west3, with N2 cpu type, only available in 2 of the 3 zone and I got this error: