Im learning about OpenStack and understand that resources of a single compute node can be allocated and shared between multiple vm instances. If we assume that I have a single application that requires resources exponentially and runs on a single vm instance. Is it possible to allocate multiple compute node resources for the single vm instance so the application is able to use more resources?
To make it more simple, I would like to be able to dedicate multiple compute nodes resources for a single application.
Best Answer
No, the current implementation of openstack doesn't allow to allocate multiple compute node resources for a single VM. You can imagine openstack compute nodes as an abstraction layer over one of the virtualization hypervisor supported by openstack (Here you can read the list of hypervisors supported https://wiki.openstack.org/wiki/HypervisorSupportMatrix ). Any of them allow to create vm using resources of multiple compute nodes.
If you have an application that requires resources exponentialy resource you could redesign it in order to distribute the computation over several node. There are many approaches in order to do it. For example if the application manages a lot of data you can try to use a big data framework as hadoop. For example if the application need many cpu resource you can use a message passing framework(example: http://www.open-mpi.org/ ) in order to syncronize the application distributed over several vm.
If you want you can distribute this application redesigned for using several VMs using openstack.