Scale pod and the volume attached to the pod
Issue
- Imagine a pod with a pv backed by a replication controller, and when scaling the pod to 2, would it be possible that the new pod will have a new volume?
I've seen in the templates (i.e.- the mysql with permanent storage), it creates the claim and then attach the volume using the claim previously created, but if I try to scale the rc, the new pod also tries to use the same volume (which fails because it is not multiwrite enabled).
Any clues? I've seen this https://github.com/openshift/origin/issues/4211 that talks about a "PersistentVolumeClaimTemplate on the RC side-by-side with the PodTemplate" and some folk asking in stackoverflow http://stackoverflow.com/questions/33313199/is-there-any-way-that-can-make-each-pod-gets-its-own-volume-in-rc-template and nothing else
A simple use case will be the one commented in the upstream issue, when a user wants to create a database cluster where every database node has its own storage. It can start with a single pod and a persistent volume attached to the pod and when scaling to >1 pod, a new pod with a proper new volume needs to be created, otherwise, the new pod will try to use the same volume and bad things can happen (data corruption)
Environment
- Openshift Enterprise 3.1
Subscriber exclusive content
A Red Hat subscription provides unlimited access to our knowledgebase, tools, and much more.