Implementation is only needed for V1 API. On Wed, May 2, 2018 at 7:31 PM Varun Gupta <var...@uber.com> wrote:
> We aggregate all the offers for a host, such that placement engine can > pack multiple tasks that can be launched on this host using aggregated > resources. If offers are unused for that host then they will be implicitly > declined. > > Placement cycle has two components > - determine tasks that can be launched on this host and enque those tasks > to be launched. > - second is to deque and launch them. > > During this placement cycle, offers can be rescinded and accordingly > placement has to be adjusted. For that we maintain second map of offer id > -> host name. > > Benefits of adding host name and agent id in rescind offer callback. > - Mutex locks to synchronize both maps, leads to some performance hit. > - Managing second map, is more code and prone to bugs. > - Little overhead on heap memory and GC. > On Wed, May 2, 2018 at 5:08 PM Benjamin Mahler <bmah...@apache.org> wrote: > >> I'm a -1 on adding redundant information in the message. >> >> The scheduler can maintain an index of offers by offer id to address this >> issue: >> >> hostname -> offers >> offer_id -> offer >> >> On Wed, May 2, 2018 at 11:39 AM, Vinod Kone <vinodk...@apache.org> wrote: >> >> > Can I ask why you are indexing the offers by hostname? Is it to better >> > handle agent removal / unreachable signal? >> > >> > Looking at the code >> > < >> https://github.com/apache/mesos/blob/master/src/master/master.cpp#L11036> >> > , >> > I think master has the requested information (agent id, hostname) so we >> can >> > include it in the rescind message! >> > >> > But there are couple things to discuss. >> > >> > The extra information to be included in rescind message is technically >> > redundant. So we need to figure out a guideline on what information >> should >> > be included / not included (e.g., should we include agent IP too) in >> such >> > calls. >> > >> > Second, adding this extra information in v1 scheduler API would be >> > relatively easy. But adding this to v0 API would be hard. Which API do >> you >> > need to be updated? >> > >> > >> > On Wed, May 2, 2018 at 10:31 AM, Varun Gupta <var...@uber.com> wrote: >> > >> > > Hi, >> > > >> > > Currently in our implementation we maintain two maps. >> > > >> > > Hostname -> []Offers >> > > >> > > offerID -> Hostname >> > > >> > > Second map is needed because rescind offers callback only provides >> > offerid >> > > and we need hostname to do performant lookup in first map. >> > > >> > > Is it feasible to add hostname or agentid in rescind offers? >> > > >> > > Thanks, >> > > Varun >> > > >> > >> >
