Moving stateless services can be trivial or a non problem, as others have suggested. Migrating state full services becomes a function of migrating the state, including any network conx, etc. To think aloud, from a bit of past considerations in hpc like systems, some systems relied upon the underlying systems to support migration (vMotion, etc.), to 3rd party libraries (was that Meiosys) that could work on existing application binaries, to libraries (BLCR <http://crd.lbl.gov/departments/computer-science/CLaSS/research/BLCR/>) that need support from application developer. I was involved with providing support for BLCR based applications. One of the challenges was the time to checkpoint an application with large memory footprint, say, 100 GB or more, which isn't uncommon in hpc. Incremental checkpointing wasn't an option, at least at that point. Regardless, Mesos' support for checkpoint-restore would have to consider the type of checkpoint-restore being used. I would imagine that the core part of the solution would be simple'ish, in providing a "workflow" for the checkpoint-restore system (sort of send signal to start checkpoint, wait certain time to complete or timeout). Relatively less simple would be the actual integration of the checkpoint-restore system and dealing with its constraints and idiosyncrasies.
On Fri, Feb 19, 2016 at 4:50 AM, Dick Davies <d...@hellooperator.net> wrote: > Agreed, vMotion always struck me as something for those monolithic > apps with a lot of local state. > > The industry seems to be moving away from that as fast as its little > legs will carry it. > > On 19 February 2016 at 11:35, Jason Giedymin <jason.giedy...@gmail.com> > wrote: > > Food for thought: > > > > One should refrain from monolithic apps. If they're small and stateless > you > > should be doing rolling upgrades. > > > > If you find yourself with one container and you can't easily distribute > that > > work load by just scaling and load balancing then you have a monolith. > Time > > to enhance it. > > > > Containers should not be treated like VMs. > > > > -Jason > > > > On Feb 19, 2016, at 6:05 AM, Mike Michel <mike.mic...@mmbash.de> wrote: > > > > Question is if you really need this when you are moving in the world of > > containers/microservices where it is about building stateless 12factor > apps > > except databases. Why moving a service when you can just kill it and let > the > > work be done by 10 other containers doing the same? I remember a talk on > > dockercon about containers and live migration. It was like: „And now > where > > you know how to do it, dont’t do it!“ > > > > > > > > Von: Avinash Sridharan [mailto:avin...@mesosphere.io] > > Gesendet: Freitag, 19. Februar 2016 05:48 > > An: user@mesos.apache.org > > Betreff: Re: Feature request: move in-flight containers w/o stopping them > > > > > > > > One problem with implementing something like vMotion for Mesos is to > address > > seamless movement of network connectivity as well. This effectively > requires > > moving the IP address of the container across hosts. If the container > shares > > host network stack, this won't be possible since this would imply moving > the > > host IP address from one host to another. When a container has its > network > > namespace, attached to the host, using a bridge, moving across L2 > segments > > might be a possibility. To move across L3 segments you will need some > form > > of overlay (VxLAN maybe ?) . > > > > > > > > On Thu, Feb 18, 2016 at 7:34 PM, Jay Taylor <outtat...@gmail.com> wrote: > > > > Is this theoretically feasible with Linux checkpoint and restore, perhaps > > via CRIU?http://criu.org/Main_Page > > > > > > On Feb 18, 2016, at 4:35 AM, Paul Bell <arach...@gmail.com> wrote: > > > > Hello All, > > > > > > > > Has there ever been any consideration of the ability to move in-flight > > containers from one Mesos host node to another? > > > > > > > > I see this as analogous to VMware's "vMotion" facility wherein VMs can be > > moved from one ESXi host to another. > > > > > > > > I suppose something like this could be useful from a load-balancing > > perspective. > > > > > > > > Just curious if it's ever been considered and if so - and rejected - why > > rejected? > > > > > > > > Thanks. > > > > > > > > -Paul > > > > > > > > > > > > > > > > > > > > -- > > > > Avinash Sridharan, Mesosphere > > > > +1 (323) 702 5245 >
