On Thu, Jun 19, 2014 at 11:33 AM, Sharma Podila <spod...@netflix.com> wrote:
> Yeah, having soft-limit for memory seems like the right thing to do > immediately. The only problem left to solve being that it would be nicer to > throttle I/O instead of OOM for high rate I/O jobs. Hopefully the soft > limits on memory push this problem to only the extreme edge cases. > The reason that Mesos uses hard limits for memory and cpu is to provide predictability for the users/tasks. For example, some users/tasks don't want to be in a place where the task has been improperly sized but was humming along fine because it was using idle resources on the machine (soft limits) but during crunch time (e.g., peak workload) cannot work as well because the machine had multiple tasks all utilizing their full allocations. In other words, this provides the users the ability to better predict their SLAs. That said, in some cases the tight SLAs probably don't make sense (e.g., batch jobs). That is the reason we let operators configure soft and hard limits for cpu. Unless I misunderstand how memory soft limits work ( https://www.kernel.org/doc/Documentation/cgroups/memory.txt) I don't see why we can't provide a similar soft limit option for memory. IOW, feel free to file a ticket :)
