Sergey, Do we have an IEP for this feature?
What should happen when on an active cluster with put operations if we receive a read-only state change request? How we guarantee that all cache operations delivered (or not yet) to backups are not rejected by applied read-only request? I haven't found such tests in your PR. I've downloaded your branch and run some tests locally. I've tried DataStreamer cache loads (allowOverwrite mode false) with a concurrent cluster change state request to read-only mode and I've got strange behaviour. My test scenario was: 1) Start DataStremer cache load; 2) change cluster to read-only state; 3) change state back to normal; When the state has been changed to `read-only` I've flooded with a lot of `Failed to perform cache operation (cluster is in read-only mode)` errors, but when I've reverted the state back the DataStreamer continue its load without any error. I think we should not allow such behaviour. We should cancel the DataStreamer task or allow it to be finished. On Fri, 31 May 2019 at 13:00, Sergey Antonov <antonovserge...@gmail.com> wrote: > > Hello, Zhenya, Maxim! > > Thank you for your replies! > > >> Should we also allow writes to the DistributedMetaStorage and if not why? > Yes. DistributedMetastorage available for updates with enabled read-only > mode. I added test about it to ClusterReadOnlyModeSelfTest > > >> What's the purpose for ignite-sys-cache updates still be available ? > ignite-sys-cache is using in the different subcomponents, for example, > security. > > чт, 30 мая 2019 г. в 20:30, Zhenya Stanilovsky <arzamas...@mail.ru.invalid>: > > > hi, Sergey. > > What's the purpose for ignite-sys-cache updates still be available ? > > > > thanks ! > > > > > Hello Igniters! > > > > > > I'm working on cluster read-only mode [1] feature. In this mode cluster > > > will be available only for read operations, all data modification > > > operations in user caches will be rejected > > > with ClusterReadOnlyModeCheckedException. This feature could be helpfull > > > for maintenance works (control.sh idle_verify/validate_indexes). > > > > > > A few points about cluster read-only mode: > > > 1) Read-only mode could be enabled on active cluster only. > > > 2) Read-only mode doens't store on PDS (i.e. after cluster restart > > > enabled > > > read-only mode will be forgotten) > > > 3) Updates to ignite-sys-cache will be available with enabled read-only > > > mode. > > > > > > More informartion about implementation you could find in PR [2]. > > > > > > What do you think about this feature? > > > > > > [1] https://issues.apache.org/jira/browse/IGNITE-11256 > > > [2] https://github.com/apache/ignite/pull/6423 > > > > > -- > BR, Sergey Antonov
