Hello, Ivan. >>What is a fundamental difference between them? On inactive cluster caches aren't started. So you can't get data from cache.
вт, 4 июн. 2019 г. в 12:16, Павлухин Иван <vololo...@gmail.com>: > Sergey, Igniters, > > Sorry if my question is not very smart. > > I am trying to think about it from a perspective of a (newbie) user. > And from the first glance it is not clear how a read-only cluster is > different from a not active cluster? What is a fundamental difference > between them? Can we combine two modes into one? If not we will need a > clear explanation for a user. > > пн, 3 июн. 2019 г. в 20:15, Maxim Muzafarov <maxmu...@gmail.com>: > > > > 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 > > > > -- > Best regards, > Ivan Pavlukhin > -- BR, Sergey Antonov
