> On Dec. 24, 2014, 12:45 a.m., Adam B wrote: > > include/mesos/mesos.proto, lines 435-437 > > <https://reviews.apache.org/r/29274/diff/1/?file=797605#file797605line435> > > > > Is there going to have to be complex verification? What happens if I > > specify a non-disk resource in before but not after, for a disk-related > > operation? What if a `before` resource doesn't actually exist? > > A declarative approach where one only specifies (an action and) the > > desired outcome would allow the recipient (master) to do whatever is > > necessary to reach the desired outcome. > > Jie Yu wrote: > My worry about specifying only the desired outcome is that sometimes it's > ambiguate (master has multiple ways to perform the transformation). I think > it's the framework who is ultimately responsible for deciding what > transformation should be performed, not master. Therefore, I still prefer the > 'current/desired' model more because the framework can clearly convey its > transforamtion decision. > > What do you think? I would like to hear comments from others as well. > > Jie Yu wrote: > One more example. If you only specify the desired outcome, how do you > specify the release of a persistent disk? The master does not know which > persistent disk the framework wants to release if we don't specify the > 'current'.
I thought about this as well and we definitely need both `current`/`desired`. We don't always know which `current` we want transformed into `desired`. The release of a persistent disk is a great example for this, another example is once we add revocable resources, we can no longer assume that the `current` will consist of only unreserved resources. - Michael ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/29274/#review65982 ----------------------------------------------------------- On Jan. 5, 2015, 8:17 p.m., Jie Yu wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/29274/ > ----------------------------------------------------------- > > (Updated Jan. 5, 2015, 8:17 p.m.) > > > Review request for mesos, Adam B, Benjamin Hindman, Ben Mahler, switched to > 'mcypark', and Vinod Kone. > > > Repository: mesos-git > > > Description > ------- > > Added Resource::Transformation to mesos.proto per our discussion in > https://reviews.apache.org/r/29173/ > > > Diffs > ----- > > include/mesos/mesos.proto 540071db64961466eb75c779b3ea6863f4594437 > > Diff: https://reviews.apache.org/r/29274/diff/ > > > Testing > ------- > > make check > > > Thanks, > > Jie Yu > >
