Hi Luke, I'll have to disagree but only semantically.
For a small environment and without changing the scheduler config, the concept of "zone" can be used. Yes, I would agree with you that in a real production environment the Red Hat concept of a "zone" is as you described. You could additionally label nodes with something like "env=appserver" and use nodeselectors on that. This is probably a more realistic production expectation. For the purposes of getting Abdala's small environment going, I guess it doesn't much "matter"... Erik M Jacobs, RHCA Principal Technical Marketing Manager, OpenShift Enterprise Red Hat, Inc. Phone: 646.462.3745 Email: [email protected] AOL Instant Messenger: ejacobsatredhat Twitter: @ErikonOpen Freenode: thoraxe On Wed, May 4, 2016 at 11:36 AM, Luke Meyer <[email protected]> wrote: > > > On Tue, May 3, 2016 at 10:57 AM, Erik Jacobs <[email protected]> wrote: > >> Hi Olga, >> >> Some responses inline/ >> >> >> Erik M Jacobs, RHCA >> Principal Technical Marketing Manager, OpenShift Enterprise >> Red Hat, Inc. >> Phone: 646.462.3745 >> Email: [email protected] >> AOL Instant Messenger: ejacobsatredhat >> Twitter: @ErikonOpen >> Freenode: thoraxe >> >> On Mon, Apr 25, 2016 at 9:34 AM, ABDALA Olga <[email protected]> >> wrote: >> >>> Hello all, >>> >>> >>> >>> I am done with my *origin advanced installation* (thanks to your useful >>> help) which architecture is composed of *4 virtualized servers* (on the >>> same network): >>> >>> - 1 Master >>> >>> - 2 Nodes >>> >>> - 1 VM hosting Ansible >>> >>> >>> >>> My next steps are to implement/test some use cases with a *three-tier >>> App*(each App’s tier being hosted on a different VM): >>> >>> - The * horizontal scalability*; >>> >>> - The * load-balancing* of the Nodes : Keep the system running >>> even if one of the VMs goes down; >>> >>> - App’s monitoring using *Origin API*: Allow the Origin API to >>> “tell” the App on which VM is hosted each tier. (I still don’t know how to >>> test that though…) >>> >>> >>> >>> There are some * notions* that are still not clear to me: >>> >>> - From my web console, how can I know *on which Node has my App >>> been deployed*? >>> >> >> If you look in the Browse -> Pods -> select a pod, you should see the >> node where the pod is running. >> >> >>> - How can I put *each component of my App* on a *separated Node*? >>> >>> - How does the “*zones*” concept in origin work? >>> >> >> These two are closely related. >> >> 1) In your case it sounds like you would want a zone for each tier: >> appserver, web server, db >> 2) This would require a node with a label of, for example, zone=appserver >> 3) When you create your pod (or replication controller, or deployment >> config) you would want to specify, via a nodeselector, which zone you want >> the pod(s) to land in >> >> > This is not the concept of zones. The point of zones is to spread replicas > between different zones in order to improve HA (for instance, define a zone > per rack, thereby ensuring that taking down a rack doesn't take down your > app that's scaled across multiple zones). > > This isn't what you want though. And you'd certainly never put a zone in a > nodeselector for an RC if you're trying to scale it to multiple zones. > > For the purpose of separating the tiers of your app, you would still want > to use a nodeselector per DC or RC and corresponding node labels. There's > no other way to designate where you want the pods from different RCs to > land. You just don't want "zones". > > > >> This stuff is scattered throughout the docs: >> >> >> https://docs.openshift.org/latest/admin_guide/manage_nodes.html#updating-labels-on-nodes >> >> https://docs.openshift.org/latest/dev_guide/deployments.html#assigning-pods-to-specific-nodes >> >> I hope this helps. >> >> >>> >>> >>> Content of /etc/ansible/hosts of my Ansible hosting VM: >>> >>> [masters] >>> >>> sv5305.selfdeploy.loc >>> >>> # host group for nodes, includes region info >>> >>> [nodes] >>> >>> sv5305.selfdeploy.loc openshift_node_labels="{'region': 'infra', 'zone': >>> 'default'}" openshift_schedulable=false >>> >>> sv5306.selfdeploy.loc openshift_node_labels="{'region': 'primary', >>> 'zone': 'east'}" >>> >>> sv5307.selfdeploy.loc openshift_node_labels="{'region': 'primary', >>> 'zone': 'west'}" >>> >>> >>> >>> Thank you in advance. >>> >>> >>> >>> Regards, >>> >>> >>> >>> Olga >>> >>> >>> >>> _______________________________________________ >>> dev mailing list >>> [email protected] >>> http://lists.openshift.redhat.com/openshiftmm/listinfo/dev >>> >>> >> >> _______________________________________________ >> dev mailing list >> [email protected] >> http://lists.openshift.redhat.com/openshiftmm/listinfo/dev >> >> >
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