openshift multi node architechture

Question

How does openshift multi node architecture work in V3 version? Does all pods gets replicated across nodes or it only gets replicated if one node goes down?

Let's say I have one master and 3 nodes, in which node application pod gets resided?

Answer 1

If you create a pod directly, it will get assigned to a single machine. OpenShift uses "replication controllers" from Kubernetes to create N copies of a pod and ensure they are running, and "deployment configs" to handle rolling out changes (changing a deployment config creates a new replication controller with the new changes, and the old replication controller is scaled down). Both replication controllers and deployment configs have a scale number that is used to control the number of copies. Pods from the same replication controller are automatically spread across different nodes.