> On April 23, 2019, 10:47 a.m., Benjamin Bannier wrote: > > docs/scheduler-http-api.md > > Line 132 (original), 132 (patched) > > <https://reviews.apache.org/r/70132/diff/5/?file=2140649#file2140649line132> > > > > What do you think of getting rid of "implicitly declined" behavior for > > "cancelling operations"? > > > > It seems that behavior is more driven by the implementation than > > intuitive api behavior; it e.g., forces frameworks to reason differently > > about operations executed in isolation vs. executed together. It seems > > having the identical behavior for both cases would both be easier to > > explain and also program against. The behavior that seems to make most > > sense for me would be to only ever implictly decline "untouched resources", > > e.g., if accepting offered `cpus:4` with `RESERVE(cpus:2, role) && > > UNRESERVE(cpus:2, role)` we would implicitly decline only `cpus:2`. > > Chun-Hung Hsiao wrote: > It seems to me that "cancelling operations" as something that are both 1. > very rare and 2. make little sense for frameworks, so I'm more like > delivering a fix for common cases without making the alrealy-messy code path > more complicated. WDYT? Also @bmahler what's your opinion on @bbannier's > suggestion? IIRC you mentioned something like some are designed behaviors > before, but I didn't know the context.
Thanks for bringing this up, it's certainly a bit bizarre of a use case. I think the more common case is UNRESERVE on its own, where it still seems a bit bizarre that the "untouched" resources are declined with the filter and the UNRESERVE resources are not filtered. That seems a bit arbitrary to me, but I'm not sure what to do about it without allowing the framework to be explicit about which part it wants to "decline and filter" when accepting, and this requires an interface change. Personally I would consider RESERVE+UNRESERVE to be "touching" those resources, but I don't think we should worry about it in this patch (I assume that wasn't your intent anyway, and you were more wanting to raise this topic for discussion?) > On April 23, 2019, 10:47 a.m., Benjamin Bannier wrote: > > src/master/master.cpp > > Lines 5963-5964 (original), 5983-5984 (patched) > > <https://reviews.apache.org/r/70132/diff/5/?file=2140650#file2140650line5983> > > > > Is this a workaround we need until MESOS-4553 gets resolved? If it is, > > let's add a `TODO`. > > Chun-Hung Hsiao wrote: > I don't know actually lol. I just copied it from > https://github.com/apache/mesos/blob/45c9788618e7123f408a1dffcf6772a1285cd2e5/src/master/master.cpp#L10969-L10972, > as @mzhu suggested that if there's an allocation in between there might be > offer fragmentation. Is this a workaround for MESOS-4553? Well, one could say all the interactions with the allocator around offers are a "workaround" until MESOS-4553 is done :) I would say that the pause/resume here is more a workaround of the limited recoverResources interface (i.e. it doesn't let you specify a collection of resources and filters, so we need to perform two calls). The only issue with pause/resume is: https://issues.apache.org/jira/browse/MESOS-9734 - Benjamin ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/70132/#review214812 ----------------------------------------------------------- On April 23, 2019, 1:15 a.m., Chun-Hung Hsiao wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/70132/ > ----------------------------------------------------------- > > (Updated April 23, 2019, 1:15 a.m.) > > > Review request for mesos, Benjamin Bannier, Benjamin Mahler, and Meng Zhu. > > > Bugs: MESOS-9616 > https://issues.apache.org/jira/browse/MESOS-9616 > > > Repository: mesos > > > Description > ------- > > Currently if a framework accepts an offer to perform pipelined > operations, e.g., reserving resource, without a final consumer, the > converted resources will be implicitly declined. This is an undesired > behavior as the framework might want to reserve one resource first but > launch a task later in the next allocation cycle. This patch fixes this > behavior. > > But, if the framework accepts an offers with multiple operations that > cancel out each other, the resources consumed by these operations are > still considered unused and will be declined. > > > Diffs > ----- > > docs/scheduler-http-api.md a5327c229142267836f327f9c382ef50b7e334db > src/master/master.cpp ad54ae217863a08f4e6d743b39c176b171353084 > src/tests/slave_tests.cpp b1c3a01031b917fb9773c8c890a8f88838870559 > > > Diff: https://reviews.apache.org/r/70132/diff/5/ > > > Testing > ------- > > make check > > > Thanks, > > Chun-Hung Hsiao > >
