Val, do you have a fix in mind? On Thu, Oct 5, 2017 at 2:50 AM, Valentin Kulichenko < valentin.kuliche...@gmail.com> wrote:
> FULL_SYNC as default is not a solution. PRIMARY_SYNC/readFromBackup is > valid combination of parameters and useful in many scenarios. For example, > what if I have a replicated cache and don't want to update all nodes > synchronously? > > The point is that get() invoked after the put() in the same thread should > always return the latest value. Now this behavior is not consistent and > depends on which nodes these operations are executed on. > > -Val > > On Wed, Oct 4, 2017 at 3:27 AM, Alexei Scherbakov < > alexey.scherbak...@gmail.com> wrote: > > > Val, > > > > Totally agreed. > > > > I think this can be easily fixed by setting FULL_SYNC as default sync > mode. > > > > Actually, I do not understand why this is not done yet. > > > > 2017-10-04 12:09 GMT+03:00 Vladislav Pyatkov <vldpyat...@gmail.com>: > > > > > Hi Val, > > > > > > If we update local backup immediate synchronously when sending commit > to > > > primary, this only partly removes questions about consistence view. > > > But we always can to get other (unpredictable) value, because another > > > transaction will be executed simultaneously from other threads. > > > > > > At the same time this is good place for optimization, probably reduce > > > network overhead. > > > I think, need to create a ticket in Jira for the improvement. > > > > > > > > > On Tue, Oct 3, 2017 at 12:27 AM, Valentin Kulichenko < > > > valentin.kuliche...@gmail.com> wrote: > > > > > > > Igniters, > > > > > > > > I noticed that combination of PRIMARY_SYNC mode and > readFromBackup=true > > > > (both are default values BTW) introduces weird semantics when reading > > > *on a > > > > backup node*. Basically, if I do put and then get for the same key in > > the > > > > same thread, I can get previous value. In my understanding, this > > happens > > > > because even local backup is updated asynchronously in this case. > > > > > > > > First of all, this is obviously confusing and would be considered as > a > > > bug > > > > by most of the users (I just updated the key with some value, why > > would I > > > > get another value when reading it?). > > > > > > > > Second of all, it seems that we send a network message from primary > > node > > > to > > > > local backup, which doesn't make much sense to me and looks like > > > > unnecessary performance overhead. > > > > > > > > Is it possible to update local backup synchronously in this scenario? > > > > > > > > -Val > > > > > > > > > > > > > > > > -- > > > Vladislav Pyatkov > > > > > > > > > > > -- > > > > Best regards, > > Alexei Scherbakov > > >
