Hi,
as part of building a small but completely new OpenStack cloud on top of Queens, I am investigating the possibilities of providing SLAs for VMs. Unfortunately, I'm still rather new to OpenStack. I have a four compute nodes with a few dozen threads each, and a few VMs on top of them. Some of my VMs occasionally need to be able to nail entire cores for optimal single-threaded performance, but are usually nearly idle. For performance and reliability reasons, I would not want all high-priority VMs be scheduled on one node only, while having the less performance-critical ones share the other nodes. So the question is how to (eg) partition nodes to have at least two compartments, and/or dynamically (re-) allocate VMs to lesser used nodes/compartments. When the load goes down again, I would like to undo squeezing the other VMs into the remaining capacity and have them spread out evenly again. For me, the critical factor is having some cores exclusively used by certain VMs, if and only as long as they require it (yes, more hardware might be on the horizon later, but there's no desire to squander the money). I've read about the FilterScheduler, which looks almost good, but I would like to apply this placement mechanism to running VMs. I am also interested in just pausing VMs for seconds in turn, if I can detect that a high-priority VM needs more capacity. But I don't see off the top of my head how to partition compute nodes. Can it be done with the NUMA configuration, and then schedule based on the individual "pieces", ie. effectively not scheduling across four nodes, but, say, 16 NUMA slices in a hierarchical setting (I haven't seen the machines yet, so I don't really know what they are)? If I could sort of put a VM through the placement algorithm so that I get the placement decision, then that's sort of fine: In that case, I'd put my other VMs through the placement algoritm and "manually" (scripted) migrate them. What is the common wisdom on these problems, please? Thanks, Toni _______________________________________________ Mailing list: http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack Post to : openstack@lists.openstack.org Unsubscribe : http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack
