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And still no way to make a simple 2-node cluster in 2 different availability zones. What if one AZ fails completely? Happens quite often. I tried to read HA do

And still no way to make a simple 2-node cluster in 2 different availability zones. What if one AZ fails completely? Happens quite often. I tried to read HA documentation on Kubernetes and it all starts with warnings like "this is fairly advanced stuff, requiring intimate knowledge of Kubernetes inner workings", and going on with pages and pages of setup process. Basic HA is not a "fairly advanced stuff", it is a commonplace requirement in any production environment. Why do I need a 1000-node cluster if all 1000 nodes are in the same AZ, which can have an outage anytime?

atemerev 11y ago
Update: docs just arrived — http://kubernetes.io/docs/admin/multiple-zones/ http://kubernetes.io/docs/admin/multiple-zones/ . That's better :)
SEJeff 11y ago
Conceptually speaking, having two nodes is not high availability, it is failover / fault tolerance. High availability is generally N + 2 where N is >= 1. This is a better explanation than I would write on this: https://www.quora.com/What-is-the-difference-between-a-highly-fault-tolerant-and-a-highly-available-system https://www.quora.com/What-is-the-difference-between-a-highl...
- atemerev 11y ago
  You are right, of course. Still, I don't understand why it is so low priority in container orchestration platforms. And how it is even possible to live without it in production.
  - beeps 11y ago
    It's not low on the priority list at all. These are the same people who worked on borg (I'm a contributor, but didn't work on borg); they get stateful applications and understand that it needs to be done RIGHT. No second chances. Nailing this for 1.0 or 1.1 would have consumed a significant portion of the team, but rest assured it will work, soon.
atemerev 11y ago
Update2: persistent volumes are still allocated only in the same AZ with master container. Hence, no HA databases (only manual volume provisioning is possible). I still wonder what is the primary use case for Kubernetes (or Docker Swarm, which has similar issues) if high availability is so low on the priority list.

atemerev 11y ago

Update: docs just arrived — http://kubernetes.io/docs/admin/multiple-zones/ http://kubernetes.io/docs/admin/multiple-zones/ . That's better :)

SEJeff 11y ago

Conceptually speaking, having two nodes is not high availability, it is failover / fault tolerance. High availability is generally N + 2 where N is >= 1. This is a better explanation than I would write on this: https://www.quora.com/What-is-the-difference-between-a-highly-fault-tolerant-and-a-highly-available-system https://www.quora.com/What-is-the-difference-between-a-highl...

atemerev 11y ago
You are right, of course. Still, I don't understand why it is so low priority in container orchestration platforms. And how it is even possible to live without it in production.
- beeps 11y ago
  It's not low on the priority list at all. These are the same people who worked on borg (I'm a contributor, but didn't work on borg); they get stateful applications and understand that it needs to be done RIGHT. No second chances. Nailing this for 1.0 or 1.1 would have consumed a significant portion of the team, but rest assured it will work, soon.

atemerev 11y ago

Update2: persistent volumes are still allocated only in the same AZ with master container. Hence, no HA databases (only manual volume provisioning is possible). I still wonder what is the primary use case for Kubernetes (or Docker Swarm, which has similar issues) if high availability is so low on the priority list.