Sure. I will have something soon with an initial draft to be reviewed within the community.
Thanks Anindya On Mon, Sep 21, 2015 at 11:14 AM, Vinod Kone <[email protected]> wrote: > I think shared persistent volumes are a great feature addition! > > Couple things that need to be addressed > > --> Who gets charged for the shared disk quota if multiple tasks share > them? I'm assuming the one who creates a RW copy? > > --> How does the resource handling logic work in Mesos if a resource is > re-offered while still in use? I think this is the piece that needs some > major thinking. > > It's worthwhile to start a design doc around this. Anindya, are you up for > the task? > > Thanks, > > On Mon, Sep 21, 2015 at 11:00 AM, Anindya Sinha <[email protected]> > wrote: > > > Now that mesos has introduced support for persistent volumes, the > > persistent volumes that are created on a specific slave is offered to the > > framework(s) as another resource. As a result, a task which needs RW > access > > to that persistent volume can use that resource. > > > > Till this task is running, that persistent volume cannot be offered to > the > > framework(s) and hence would not be available for another task running on > > the same agent. > > > > Let us consider an use case wherein a service needs access to the same > > persistent volume from multiple task instances running on the same agent > > simultaneously, ie. when both (or multiple) of such task instances are > > RUNNING. Since the persistent volume is not offered as a resource to the > > framework(s) till a task that has grabbed it is still active, the > > subsequent instances needed access to the same persistent volume is not > > feasible. > > > > To alleviate that scenario, we propose making persistent volumes > "sharable" > > (as optional). Default behavior can still be "non-sharable" but > frameworks > > may want to CREATE persistent volumes as "sharable" (which would need an > > optional field in Resources.DiskInfo.Persistence). Hence, we would allow > > "sharable" persistent volumes be offered as resources to the framework(s) > > [matching role] even if it has been grabbed by a task already running on > > the agent, so as that subsequent tasks can use that persistent volume. > > > > Comments/concerns? > > > > Thanks > > > > Anindya > > >
