I had this thought when exploring this parameter at first and only was able to change my understanding when evaluating it more deeply in the source and reaching out to other users/devs.
There could be an issue with new users who think increasing the hb frequency will impact inter-node failure detection - so people might tweak it thinking it does something it doesn't. I think renaming it could help avoid this. This is because other systems use heartbeat frequencies for failure detection protocols under the hood so people may be coming with this understanding and think that's what this parameter is for. On Tue, Feb 28, 2017 at 9:16 AM Denis Magda <dma...@apache.org> wrote: > They expect exactly what the name of the > TcpDiscoverySpi.heartbeatsFrequency method says - rate of heartbeats will > be adjusted if you play with this parameter. > > However, this is not true because the frequency of heartbeats is > calculated from the failure detection timeout. > > — > Denis > > > On Feb 28, 2017, at 7:28 AM, Yakov Zhdanov <yzhda...@apache.org> wrote: > > > > Denis, I did not get your last message. What did users expect from > changing > > hbFreq? > > > > --Yakov > > > > 2017-02-28 4:08 GMT+03:00 Dmitriy Setrakyan <dsetrak...@apache.org>: > > > >> Yakov, what do you think? > >> > >> On Mon, Feb 27, 2017 at 4:17 PM, Denis Magda <dma...@apache.org> wrote: > >> > >>> Frankly, I decided to initiate this discussion after talking to many > >>> Apache Ignite users who had initially thought that TcpDiscoverySpi. > >> heartbeatsFrequency > >>> manages the heartbeats and they had tried to tweak it not getting a > >> desired > >>> outcome. Even more, TcpDiscoverySpi.heartbeatsFrequenc’s javadoc > already > >>> states that this is for metrics frequency only but looks like the guys > >>> hadn’t note this. > >>> > >>> So, personally, yes I would break the compatibility here which is fine > to > >>> do in 2.0. > >>> > >>> — > >>> Denis > >>> > >>>> On Feb 27, 2017, at 3:59 PM, Dmitriy Setrakyan <dsetrak...@apache.org > > > >>> wrote: > >>>> > >>>> To me it sounds rather as an aesthetic change. Is it really worth > >>> breaking > >>>> the API for this? > >>>> > >>>> On Mon, Feb 27, 2017 at 3:30 PM, Denis Magda <dma...@apache.org> > >> wrote: > >>>> > >>>>> The heartbeats frequency has to be lower than the failure detection > >>>>> timeout. This is why we decided to calculate the former basing on a > >>> value > >>>>> set for the latter rather than making a user to adjust both > properties > >>>>> properly. This is how both parameters became related some time ago :) > >>>>> > >>>>> Honestly, I don’t think that the javadoc improvement will make things > >>>>> clearer for the users. Hope you will agree that people pay attention > >> to > >>> the > >>>>> naming first and, only if the naming makes sense to them, learn more > >>> about > >>>>> the details referring to the javadoc. > >>>>> > >>>>> — > >>>>> Denis > >>>>> > >>>>>> On Feb 27, 2017, at 2:59 PM, Dmitriy Setrakyan < > >> dsetrak...@apache.org> > >>>>> wrote: > >>>>>> > >>>>>> Hm... I don't think that heartbeat frequency has to be associated > >> with > >>>>>> failure detection. What if we just update the javadoc for this > >>> parameter, > >>>>>> stating that it has to do with metrics update only? > >>>>>> > >>>>>> On Mon, Feb 27, 2017 at 11:44 AM, Denis Magda <dma...@apache.org> > >>> wrote: > >>>>>> > >>>>>>> Igniters, > >>>>>>> > >>>>>>> Long time ago we updated the logic in discovery SPI that issues > >>>>> heartbeats > >>>>>>> messages from one node to another. Presently, heartbeats frequency > >> is > >>>>>>> calculated basing on IgniteConfiguration.failureDetectionTimeout > >>>>> meaning > >>>>>>> that TcpDiscoverySpi.heartbeatsFrequency has nothing to do with > >>>>>>> heartbeats frequency at all. > >>>>>>> > >>>>>>> TcpDiscoverySpi.heartbeatsFrequency defines a frequency for metrics > >>>>>>> message. So, I propose to rename this method in Apache Igntie 2.0 > to > >>>>>>> something more meaningful like TcpDiscoverySpi. > >>> metricsUpdateFrequency? > >>>>>>> > >>>>>>> Do you agree? Alternatives thoughts? > >>>>>>> > >>>>>>> — > >>>>>>> Denis > >>>>> > >>>>> > >>> > >>> > >> > >
