> On July 13, 2015, 4:46 p.m., Alexander Rukletsov wrote: > > src/master/http.cpp, line 507 > > <https://reviews.apache.org/r/35702/diff/9/?file=994080#file994080line507> > > > > The code until this line is basically request validation and > > authorization. Though it's not how we do it now, do you think it makes > > sense to split the function into smaller logical parts? > > > > How about something like this: > > > > ``` > > Future<Response> Master::Http::reserve(const Request& request) const > > { > > return Master::Http::reserveValidate(); > > } > > > > Future<Response> Master::Http::reserveValidate(const Request& request) > > const > > { > > <...> > > return Master::Http::reserveAuthorize(); > > } > > > > <...> > > ``` > > Michael Park wrote: > Yeah, I think it does make sense to break huge functions down to the > smaller logical pieces. I think we can do a more general refactoring for the > validation pattern, since they all pretty much do the same thing. But I think > we can consider doing that uniformly, outside of this patch. What do you > think? > > Alexander Rukletsov wrote: > I personally prefer sacrificing consistency, but write new code "right". > However, generally we tend to favour consistency over local improvements, so > feel free to "fix" the issue by creating a JIRA : ).
I've filed a JIRA ticket for this here: https://issues.apache.org/jira/browse/MESOS-3186 - Michael ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/35702/#review91472 ----------------------------------------------------------- On July 31, 2015, 9:56 p.m., Michael Park wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/35702/ > ----------------------------------------------------------- > > (Updated July 31, 2015, 9:56 p.m.) > > > Review request for mesos, Adam B, Benjamin Hindman, Ben Mahler, Jie Yu, Joris > Van Remoortere, and Vinod Kone. > > > Bugs: MESOS-2600 > https://issues.apache.org/jira/browse/MESOS-2600 > > > Repository: mesos > > > Description > ------- > > This involved a lot more challenges than I anticipated, I've captured the > various approaches and limitations and deal-breakers of those approaches > here: [Master Endpoint Implementation > Challenges](https://docs.google.com/document/d/1cwVz4aKiCYP9Y4MOwHYZkyaiuEv7fArCye-vPvB2lAI/edit#) > > Key points: > > * This is a stop-gap solution until we shift the offer creation/management > logic from the master to the allocator. > * `updateAvailable` and `updateSlave` are kept separate because > (1) `updateAvailable` is allowed to fail whereas `updateSlave` must not. > (2) `updateAvailable` returns a `Future` whereas `updateSlave` does not. > (3) `updateAvailable` never leaves the allocator in an over-allocated state > and must not, whereas `updateSlave` does, and can. > * The algorithm: > * Initially, the master pessimistically assume that what seems like > "available" resources will be gone. > This is due to the race between the allocator scheduling an `allocate` > call to itself vs master's `allocator->updateAvailable` invocation. > As such, we first try to satisfy the request only with the offered > resources. > * We greedily rescind one offer at a time until we've rescinded > sufficiently many offers. > IMPORTANT: We perform `recoverResources(..., Filters())` rather than > `recoverResources(..., None())` so that we can pretty much always win the > race against `allocate`. > In the case that we lose, no disaster occurs. We simply fail > to satisfy the request. > * If we still don't have enough resources after resciding all offers, be > optimistic and forward the request to the allocator since there may be > available resources to satisfy the request. > * If the allocator returns a failure, report the error to the user with > `PreconditionFailed`. This could be updated to be `Forbidden`, or `Conflict` > maybe as well. We'll pick one eventually. > > This approach is clearly not ideal, since we would prefer to rescind as > little offers as possible. > The challenges of implementing the ideal solution in the current state is > described in the document above. > > TODO(mpark): Add more comments and test cases. > > > Diffs > ----- > > src/master/http.cpp 3772e39015a22655dcad00ad844dc5ddc90db43f > src/master/master.hpp ea18c4e0bb0743747401b9cd5ea14ae9b56ae3cc > src/master/master.cpp 351a3c2b5f551ad065682cea601d2436258e4544 > src/master/validation.hpp 43b8d84556e7f0a891dddf6185bbce7ca50b360a > src/master/validation.cpp ffb7bf07b8a40d6e14f922eabcf46045462498b5 > > Diff: https://reviews.apache.org/r/35702/diff/ > > > Testing > ------- > > `make check` > > > Thanks, > > Michael Park > >
