Alex and all, > From a user's point of view: > Inactive cluster - deny writes, deny reads. > Read-only cluster - deny writes, allow reads.
I would be great to explain what is the need to deny both reads and writes. What tasks are not possible to solve when cluster is in read-only state? ср, 5 июн. 2019 г. в 11:55, Alex Plehanov <plehanov.a...@gmail.com>: > > Ivan, > > From a user's point of view: > Inactive cluster - deny writes, deny reads. > Read-only cluster - deny writes, allow reads. > > ср, 5 июн. 2019 г. в 10:44, Павлухин Иван <vololo...@gmail.com>: > > > Sergey, > > > > > On inactive cluster caches aren't started. So you can't get data from > > cache. > > > > As a user I do not understand what does it mean for cache to be > > started. IgniteCache does not provide start/stop methods. > > > > I am trying to figure out why there should be 2 modes (not from an > > implementation point of view but from a user one). And my concerns are > > simple. Supporting 2 modes (and 4 combinations) can make more complex > > both an experience for users and a maintenance for developers. > > > > вт, 4 июн. 2019 г. в 16:30, Sergey Antonov <antonovserge...@gmail.com>: > > > > > > Maxim, thank you for reproducer. It looks like a bug. I will fix it! > > > > > > вт, 4 июн. 2019 г. в 15:58, Maxim Muzafarov <maxmu...@gmail.com>: > > > > > > > >> We throw CacheException on each update to read-only cluster. User > > code > > > > must handle CacheException correctly .You could find test on it in > > > > ClusterReadOnlyModeTest#testDataStreamerReadOnly() > > > > > > > > In this test, DataStreamer starts when the cluster already changes its > > > > mode, but not before. Please, check my reproducer [1]. CacheException > > > > is not thrown. Am I missing something? > > > > > > > > [1] > > > > > > https://github.com/Mmuzaf/ignite/blob/readonly_streamer/modules/core/src/test/java/org/apache/ignite/internal/processors/cache/ClusterReadOnlyModeTest.java#L72 > > > > > > > > On Tue, 4 Jun 2019 at 14:42, Sergey Antonov <antonovserge...@gmail.com > > > > > > > wrote: > > > > > > > > > > Hello, Maxim! > > > > > > > > > > >> Do we have an IEP for this feature? > > > > > No, we don't have. > > > > > > > > > > >> How we guarantee that all cache operations delivered (or not yet) > > to > > > > > backups are not rejected by applied read-only request? > > > > > I reused cluster activation mechanism. So enabling read-only mode > > > > generates > > > > > an exchange on cluster. Cluster exchange guarantees update > > consistency > > > > > between primary and backups. > > > > > > > > > > >> We should cancel the DataStreamer task or allow it to be finished. > > > > > We throw CacheException on each update to read-only cluster. User > > code > > > > must > > > > > handle CacheException correctly .You could find test on it in > > > > > ClusterReadOnlyModeTest#testDataStreamerReadOnly() > > > > > > > > > > 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 > > > > > > > > > > > > > > > > > > > > > -- > > > > > BR, Sergey Antonov > > > > > > > > > > > > > -- > > > BR, Sergey Antonov > > > > > > > > -- > > Best regards, > > Ivan Pavlukhin > > -- Best regards, Ivan Pavlukhin
