Denis, This feature should not be enabled by default as it negatively affects read performance.
On Tue, Oct 3, 2017 at 10:31 PM, Denis Magda <dma...@apache.org> wrote: > Sam, > > Is there any technical limitation that prevents us from assigning caches > with similar parameters to relevant groups on-the-fly? > > After finishing the doc, I’m convinced the feature should be enabled by > default unless there are some pitfalls not known by me. > > BTW, decided to avoid logical caches term usage falling back to vivid > cache groups notion: > https://apacheignite.readme.io/docs/cache-groups < > https://apacheignite.readme.io/docs/cache-groups> > > — > Denis > > > On Oct 3, 2017, at 12:10 AM, Semyon Boikov <sboi...@gridgain.com> wrote: > > > > Hi, > > > > Regarding question about default cache group: by default cache groups > are > > not enabled, each cache is started in separate group. Cache group is > > enabled only if groupName is set in CacheConfiguration. > > > > Thanks > > > > On Sat, Sep 30, 2017 at 11:55 PM, <dsetrak...@apache.org> wrote: > > > >> Why not? Obviously compression would have to be enabled per group, not > per > >> cache. > >> > >> D. > >> > >> On Sep 29, 2017, 10:50 PM, at 10:50 PM, Vladimir Ozerov < > >> voze...@gridgain.com> wrote: > >>> And it will continue hitting us in future. For example, when data > >>> compression is implemented, for logical caches compression rate will be > >>> poor, as it would be impossbile to build efficient dictionaries in > >>> mixed > >>> data pages. > >>> > >>> On Sat, Sep 30, 2017 at 8:48 AM, Vladimir Ozerov <voze...@gridgain.com > > > >>> wrote: > >>> > >>>> Folks, > >>>> > >>>> Honesly, to me logical caches appears to be a dirty shortcut to > >>> mitigate > >>>> some inefficient internal implementation. Why can't we merge > >>> partition maps > >>>> in runtime? This should not be a problem for context-independent > >>> affinity > >>>> functions (e.g. RendezvousAffinityFunction). From user perspective > >>> logic > >>>> caches feature is: > >>>> 1) Bad API. One cannot define group configuration. All you can do is > >>> to > >>>> define group name on cache lavel and hope that nobody started another > >>> cache > >>>> in the same group with different configuration before. > >>>> 2) Performance impact for scans, as you have to iterate over mixed > >>> data. > >>>> > >>>> Couldn't we fix partition map problem without cache groups? > >>>> > >>>> On Sat, Sep 30, 2017 at 2:35 AM, Denis Magda <dma...@apache.org> > >>> wrote: > >>>> > >>>>> Guys, > >>>>> > >>>>> Another question. Does this capability enabled by default? If yes, > >>> how do > >>>>> we decide which group a cache goes to? > >>>>> > >>>>> — > >>>>> Denis > >>>>> > >>>>>> On Sep 29, 2017, at 3:58 PM, Denis Magda <dma...@apache.org> > >>> wrote: > >>>>>> > >>>>>> Igniters, > >>>>>> > >>>>>> I’ve put on paper the feature from the subj: > >>>>>> https://apacheignite.readme.io/docs/logical-caches < > >>>>> https://apacheignite.readme.io/docs/logical-caches> > >>>>>> > >>>>>> Sam, will appreciate if you read through it and confirm I > >>> explained the > >>>>> topic 100% technically correct. > >>>>>> > >>>>>> However, are there any negative impacts of having logical caches? > >>> This > >>>>> page has “Possible Impacts” section unfilled: > >>>>>> https://cwiki.apache.org/confluence/display/IGNITE/Logical+Caches > >>> < > >>>>> https://cwiki.apache.org/confluence/display/IGNITE/Logical+Caches> > >>>>>> > >>>>>> — > >>>>>> Denis > >>>>> > >>>>> > >>>> > >> > >
