Hi Vinod: Yeah, `CLEAR_FILTERS` sounds good.
UNSUPPRESS should be used whenever currently suppressed framework wants to resume getting offers after a previous SUPPRESS call. As for `CLEAR_FILTERS`, the short (but not very useful) suggestion is to call it whenever the framework wants to clear all the existing filters. To elaborate it, frameworks decline and accumulate filters when it is trying to satisfy a particular set of requirements/constraints to perform an operation. Once the operation is done and the next operation comes, if the new operation has the same (or strictly more) resource requirements/constraints compared to the last one, then it is more efficient to KEEP the existing filters instead of getting useless offers and rebuild the filters again. On the other hand, if the requirements/constraints are different (i.e. some of the previous requirements could be loosened), then it means the existing filter no longer make sense. Then it might be a good idea to clear all the existing filters to improve the chance of getting more offers. Note, although we introduce `CLEAR_FILTERS` as part of decoupling the `REVIVE` call, its usage should be independent of suppression/revival. The decision to clear the filters only depends on whether the existing filters make sense for the current operation constraints/requirements. Examples: If a framework first launches a task, then wants to launch a replacement task (because the first task failed), then it should keep the filters built up during the first launch. However, if the framework wants to launch a second task with a completely different resource profile, then clearing filters might help to get more (otherwise filtered) offers and hence speed up the deployment. -Meng On Mon, Dec 3, 2018 at 12:40 PM Vinod Kone <vinodk...@apache.org> wrote: > Hi Meng, > > What would be the recommendation for framework authors on when to use > UNSUPPRESS vs CLEAR_FILTER? > > Also, should it CLEAR_FILTERS instead of CLEAR_FILTER? > > On Mon, Dec 3, 2018 at 2:26 PM Meng Zhu <m...@mesosphere.com> wrote: > >> Hi: >> >> tl;dr: We are proposing to add two new V1 scheduler APIs: unsuppress and >> clear_filter in order to decouple the dual-semantics of the current revive >> call. >> >> As pointed out in the Mesos framework scalability guide >> <http://mesos.apache.org/documentation/latest/app-framework-development-guide/#multi-scheduler-scalability>, >> utilizing the suppress >> <http://mesos.apache.org/documentation/latest/scheduler-http-api/#suppress> >> call is the key to get your cluster to a large number of frameworks >> <https://schd.ws/hosted_files/mesoscon18/84/Scaling%20Mesos%20to%20Thousands%20of%20Frameworks.pdf>. >> In short, when a framework is idling with no intention to launch any tasks, >> it should suppress to inform the Mesos to stop sending any more offers. And >> the framework should revive >> <http://mesos.apache.org/documentation/latest/scheduler-http-api/#revive> >> when new work arrives. This way, the allocator will skip the framework when >> performing resource allocations. As a result, thorny issues such as offer >> starvation and resource fragmentation would be greatly mitigated. >> >> That being said. The suppress/revive calls currently are a little bit >> unwieldy due to MESOS-9028 >> <https://issues.apache.org/jira/browse/MESOS-9028>: >> >> The revive call has two semantics. It unsuppresses the framework AND >> clears all the existing filters. The later makes the revive call >> non-idempotent. And sometimes users may want to keep the existing filters >> when reiving which is not possible atm. >> >> To decouple the semantics, as suggested in the ticket, we propose to add >> two new V1 scheduler calls: >> >> (1) `UNSUPPRESS` call requests the Mesos to resume sending offers; >> (2) `CLEAR_FILTER` call will explicitly clear all the existing filters. >> >> To make life easier, both calls will return 200 OK (as opposed to 202 >> returned by most existing scheduler calls, including `SUPPRESS` and >> `REVIVE`). >> >> We will keep the revive call and its semantics (i.e. unsupppress AND >> clear filters) for backward compatibility. >> >> Note, the changes are proposed for V1 API only. Thus, once the changes >> are landed, framework developers are encouraged to move to V1 API to take >> advantage of the new calls (among many other benefits). >> >> Any feedback/comments are welcome. >> >> -Meng >> >
