All good stuff, thanks. > I think most of the research is going into "VM" rather than "process" migrations given most computing is going in that direction. Th

All good stuff, thanks. > I think most of the research is going into "VM" rather than "process" migrations given most computing is going in that direction. The VM-migration-over-RDMA paper you cite is interesting, at the very least, because it gives current upper bounds on the wait time for that operation. They do mention there's application downtime. This might not matter at all for scientific / HPC computing (the paper chooses CFD as a benchmark), but it definitely matters to people building highly available services, which I'd guess is most of HN. Application downtime on a single migrating VM isn't a dealbreaker, but it does assume you've either cleverly replicated state across VM instances, or you've got some other load-balancing infrastructure that's routing traffic in front of a mostly stateless app tier. In either case, you have to be careful with state, and careful operationally as you bring these things up and down. Wouldn't it be nice if the OS just did this for you? That's all I'm saying. I can't remember the last time I migrated a running process from CPU0 to CPU1 by hand. Or even wrote a script to do that. > The high-performance part of CompSci has mostly shifted in that direction since most industry and FOSS have shifted toward containers/VM's. It most certainly has. We might be at a local optimum though, and one determined by increasingly irrelevant computing history. I think about that every time I rent a VM to stand up a Unix box to run a container to run what's supposed to be a totally stateless application. Seriously, at that point, why aren't we running side-effect-free FP code as close to the metal as possible? We've got all these PCs laying around, we've got the peace dividends of the smartphone wars kicking in, we've got almost 50 years of Unix, we don't talk about the Von Neumann architecture anymore because everything is Von Neumann, etc. From my perspective it sure looks like we're surrounded by hammers. If we happen to be living in the Nail Universe, there's nothing wrong with that. > The point of my original comment, though, was to say that what you say needs to be done has been happening for a while. I'm very interested in the history of distributed computing -- tons to learn there. "Relearn" might be more accurate. At the same time, I don't trust anything pre-CAP-theorem to work at datacenter-scales. We simply didn't understand the scale problems well enough before the early 2000s.