Also, can you explain a bit more on what your "tasks" are? Since tasks are essentially units of work, it seems odd that you want to have tasks that do not take up any cpu/mem. If a task is a unix process, it has to use some cpu/mem.
On Thu, Aug 29, 2013 at 8:09 PM, Benjamin Mahler <[email protected]>wrote: > Does that mean your framework only works correctly with slaves using > process isolation? With the technique you mentioned, the tasks will get > very little cpu when cgroups isolation is running on the slave. Perhaps it > would be better to choose some sensible defaults for cpu and memory? > > > On Thu, Aug 29, 2013 at 2:51 PM, Li Jin <[email protected]> wrote: > >> I see. Things are easier when the users can always specify cpu and mem. >> However, one use case I would like to support in my framework is to allow >> users to not specify cpu and mem, and just use the process isolation. I am >> wondering if this is a supported use case. One way to make it work now is >> to use somethig like cpu=0.00001 but that feels pretty hacky. >> >> Li >> >> >> On Thu, Aug 29, 2013 at 5:13 PM, Benjamin Hindman < >> [email protected]> wrote: >> >>> Resources like cpu and memory are "grandfathered in" as first-class >>> resources. We won't be adding any other resource values like that unless >>> the community felt otherwise. Instead, as we add new resources we'll have >>> sensible defaults so your framework won't break by you might not get the >>> performance you want unless you explicitly set the resource value yourself. >>> But this should at least give you a sensible path to upgrade your framework! >>> >>> >>> On Thu, Aug 29, 2013 at 1:47 PM, Li Jin <[email protected]> wrote: >>> >>>> Ben, >>>> >>>> Thanks for the reply. So my understanding is if some isolation module >>>> (in this case cgroups) needs certain resource values to be specified, I >>>> would need to specify those even if I am using a different isolation >>>> module, is that right? I am a bit worried that future releases might >>>> require other resource values to be specified that would break my >>>> framework. >>>> >>>> Li >>>> >>>> >>>> On Thu, Aug 29, 2013 at 3:10 PM, Benjamin Hindman < >>>> [email protected]> wrote: >>>> >>>>> When we attempt to isolate the resources via control groups on Linux >>>>> we need at least some value. That being said, isolation is coarser grained >>>>> than what you can specify with a double, and 0.0001 gets rounded to a >>>>> different value (via cpu shares). I could imagine doing validation on cpu >>>>> resources to not allow something below the granularity that we can >>>>> actually >>>>> isolate. How does that sound? >>>>> >>>>> >>>>> On Thu, Aug 29, 2013 at 8:58 AM, Li Jin <[email protected]> wrote: >>>>> >>>>>> Hello guys, >>>>>> >>>>>> I have observed this behavior: >>>>>> >>>>>> (1) If I launchTasks with a task with no resource spec, mesos says >>>>>> "Error validating task 6901953 : Task uses no resources" >>>>>> (2) If I launchTasks with a task with cpu=0.00001 and no other >>>>>> resource spec, mesos launches the task >>>>>> >>>>>> These two seem to be practically the same, I am wondering what's the >>>>>> rationale to have different behavior for these two cases. >>>>>> >>>>>> Thanks, >>>>>> Li >>>>>> >>>>> >>>>> >>>> >>> >> >
