> 1. What is expected behaviour if an old thin client requests creation of > LOCAL cache on the newest ignite cluster? Unsupported operation exception.
> 2. Should we completely remove LOCAL caches support in thin clients (i.e. pyignite) before 2.13 release? Removal should happen at 2.13. On Tue, Sep 14, 2021 at 10:30 AM Ivan Daschinsky <ivanda...@gmail.com> wrote: > >> 2. 2.13 - complete removal LOCAL caches from codebase. > Let's discuss this step with more details. > 1. What is expected behaviour if an old thin client requests creation of > LOCAL cache on the newest ignite cluster? > 2. Should we completely remove LOCAL caches support in thin clients (i.e. > pyignite) before 2.13 release? > > вт, 14 сент. 2021 г. в 10:11, Nikolay Izhikov <nizhi...@apache.org>: > > > I proposed the following plan: > > > > 1. 2.12 - deprecation of LOCAL caches. > > 2. 2.13 - complete removal LOCAL caches from codebase. > > > > > 13 сент. 2021 г., в 13:30, Ivan Daschinsky <ivanda...@gmail.com> > > написал(а): > > > > > > I personally support deprecation, but we should at least have a plan. > > > I suppose that putting annotations and removing documentation are not > > > enough. > > > > > > > > > пн, 13 сент. 2021 г. в 13:22, Maxim Muzafarov <mmu...@apache.org>: > > > > > >> Ivan, > > >> > > >> I don't think we can remove LOCAL caches at the nearest time, so there > > >> is no plan for that. I can only imagine a single release that will > > >> contain all the breaking changes we want to apply in 2.x version. > > >> > > >> My point here is only about deprecation: > > >> - there are a lot of motivation points to remove written in this > thread; > > >> - I always hear from the support team that they do not recommend using > > >> local caches; > > >> - I haven't seen any bugs fixed for a long time for local caches > > >> (suppose that we are not maintaining them); > > >> > > >> I just want to make sure that all these points are reflected in the > > >> code base, so propose to mark them as deprecated. > > >> > > >> On Mon, 13 Sept 2021 at 11:29, Ivan Daschinsky <ivanda...@gmail.com> > > >> wrote: > > >>> > > >>> Hi, Maxim. And what is the plan of removing this functionality? And I > > >> also > > >>> have some questions regarding deprecation in binary protocol > > >>> > > >>> Currently thin client binary protocol > > >>> 1. Does support LOCAL caches > > >>> 2. Does not support node filters. > > >>> > > >>> I can hardly imagine the usefulness of this feature on thin clients, > > >>> especially with partition awareness, but nevertheless. > > >>> What is expected behaviour if this feature is removed from newest > > version > > >>> of Apache Ignite server and and and old client is requesting > > >>> creation of LOCAL cache? > > >>> > > >>> вс, 12 сент. 2021 г. в 15:10, Maxim Muzafarov <mmu...@apache.org>: > > >>> > > >>>> Folks, > > >>>> > > >>>> Let's get back to the discussion of obsolete LOCAL caches since a > lot > > >>>> of time has passed since the last discussion. > > >>>> I've created an issue [1] for deprecation. Let's deprecate them at > > >>>> least at the next 2.12 release. > > >>>> > > >>>> WDYT? > > >>>> > > >>>> > > >>>> [1] https://issues.apache.org/jira/browse/IGNITE-15499 > > >>>> > > >>>> On Fri, 27 Jul 2018 at 20:59, Valentin Kulichenko > > >>>> <valentin.kuliche...@gmail.com> wrote: > > >>>>> > > >>>>> Guys, > > >>>>> > > >>>>> Use cases for local caches are rare, but they definitely exist. I > > >> don't > > >>>>> think it's a very good idea to deprecate this functionality at this > > >>>> point. > > >>>>> > > >>>>> At the same point, it's obviously not the most critical part of the > > >>>>> product, so maintaining the whole separate implementation for it is > > >>>>> probably an overkill. We had exact same story with replicated > caches > > >> btw > > >>>> - > > >>>>> they were implemented separately which caused maintainability > > >> issues, and > > >>>>> we ended up removing this separate implementation. If we have the > > >> same > > >>>>> situation here, let's use the same solution. > > >>>>> > > >>>>> -Val > > >>>>> > > >>>>> On Fri, Jul 27, 2018 at 3:05 AM Dmitry Pavlov < > dpavlov....@gmail.com > > >>> > > >>>> wrote: > > >>>>> > > >>>>>> Hi Dmitriy, > > >>>>>> > > >>>>>> I would like to stress this: I'm not saying local cache it > > >> useless. I'm > > >>>>>> supposing it is not used widely. I want to figure out if I'm > > >> mistaking. > > >>>>>> > > >>>>>> All folks involved into user list says it is not used, so why not > > >> to > > >>>>>> deprecate? If we make a mistake, somebody will come to user list > > >> and > > >>>> say, > > >>>>>> 'Hey, why did you deprecate this, it is used for... in my project' > > >>>>>> > > >>>>>> Being very experienced Igniter you probably know real life usage > > >>>> examples. > > >>>>>> And I appreciate if you or somebody else in community could share > > >> it. > > >>>>>> > > >>>>>> Sincerely, > > >>>>>> Dmitriy Pavlov > > >>>>>> > > >>>>>> пт, 27 июл. 2018 г. в 1:04, Dmitriy Setrakyan < > > >> dsetrak...@apache.org>: > > >>>>>> > > >>>>>>> Guys, > > >>>>>>> > > >>>>>>> I just want to make sure we are all on the same page. The main > > >> use > > >>>> case > > >>>>>> for > > >>>>>>> LOCAL caches is to have a local hash map querable with SQL and > > >>>>>>> automatically persisted to a 3rd party DB. > > >>>>>>> > > >>>>>>> I want to discourage people from saying "nobody needs some > > >> feature". > > >>>> None > > >>>>>>> of the people in this discussion are users of any features - we > > >> are > > >>>> all > > >>>>>>> developers of the features. Instead of guessing whether to > > >> deprecate > > >>>>>>> something or not, I would actually see if it is even worth a > > >>>> discussion. > > >>>>>>> How much effort is required to fix the bug found in the LOCAL > > >> cache? > > >>>>>>> > > >>>>>>> D. > > >>>>>>> > > >>>>>>> On Thu, Jul 26, 2018 at 12:19 PM, Dmitry Pavlov < > > >>>> dpavlov....@gmail.com> > > >>>>>>> wrote: > > >>>>>>> > > >>>>>>>> Hi Alexey, > > >>>>>>>> > > >>>>>>>> There is nothing to be sorry about :) Сommunity appreciates an > > >>>>>>> alternative > > >>>>>>>> vision, this allows us to make as informed decisions as it > > >>>> possible. > > >>>>>>>> > > >>>>>>>> Thank you for finding this fact, it is very interesting. > > >>>>>>>> > > >>>>>>>> I'm not sure all these examples were prepared by experienced > > >> Ignite > > >>>>>>> users. > > >>>>>>>> So idea of deprecation may have one more argument. Deprecation > > >> will > > >>>>>> help > > >>>>>>> us > > >>>>>>>> to inform users about LOCAL cache: Probably local cache is not > > >> what > > >>>>>> they > > >>>>>>>> need. > > >>>>>>>> > > >>>>>>>> Sincerely, > > >>>>>>>> Dmitriy Pavlov > > >>>>>>>> > > >>>>>>>> чт, 26 июл. 2018 г. в 16:57, Alexey Zinoviev < > > >>>> zaleslaw....@gmail.com>: > > >>>>>>>> > > >>>>>>>>> Sorry, guys, I'll put my 1 cent > > >>>>>>>>> > > >>>>>>>>> I'd like this idea "Implement LOCAL caches as PARTITIONED > > >> caches > > >>>>>> over > > >>>>>>>> the > > >>>>>>>>> local node." > > >>>>>>>>> It make sense for examples/testing in pseudo-distributed mode > > >>>> and so > > >>>>>>> far. > > >>>>>>>>> > > >>>>>>>>> But I think that the deprecation based on user-list mentions > > >> is a > > >>>>>> wrong > > >>>>>>>>> way. Please look here > > >>>>>>>>> > > >>>>>> > > >> > https://github.com/search?q=%22CacheMode.LOCAL%22+%26+ignite&type=Code > > >>>>>>>>> There a lot of hello world examples with LOCAL mode. > > >>>>>>>>> > > >>>>>>>>> And of course, we can ask about that on user-list, not here, > > >> to > > >>>> vote > > >>>>>>> for > > >>>>>>>>> the deprecation like this. > > >>>>>>>>> > > >>>>>>>>> 2018-07-26 11:23 GMT+03:00 Vladimir Ozerov < > > >> voze...@gridgain.com > > >>>>> : > > >>>>>>>>> > > >>>>>>>>>> I meant LOCAL + non-LOCAL transactions of course. > > >>>>>>>>>> > > >>>>>>>>>> On Wed, Jul 25, 2018 at 10:42 PM Dmitriy Setrakyan < > > >>>>>>>>> dsetrak...@apache.org> > > >>>>>>>>>> wrote: > > >>>>>>>>>> > > >>>>>>>>>>> Vladimir, > > >>>>>>>>>>> > > >>>>>>>>>>> Are you suggesting that a user cannot span more than one > > >>>> local > > >>>>>>> cache > > >>>>>>>>> in a > > >>>>>>>>>>> cross cache LOCAL transactions. This is extremely > > >> surprising > > >>>> to > > >>>>>> me, > > >>>>>>>> as > > >>>>>>>>> it > > >>>>>>>>>>> would require almost no effort to support it. As far as > > >>>> mixing > > >>>>>> the > > >>>>>>>>> local > > >>>>>>>>>>> caches with distributed caches, then I agree, cross-cache > > >>>>>>>> transactions > > >>>>>>>>> do > > >>>>>>>>>>> not make sense. > > >>>>>>>>>>> > > >>>>>>>>>>> I am not sure why deprecating local caches has become a > > >>>> pressing > > >>>>>>>>> issue. I > > >>>>>>>>>>> can see that there are a few bugs, but why not just fix > > >> them > > >>>> and > > >>>>>>> move > > >>>>>>>>> on? > > >>>>>>>>>>> Can someone explain why supporting LOCAL caches is such a > > >>>> burden? > > >>>>>>>>>>> > > >>>>>>>>>>> Having said that, I am not completely opposed to > > >> deprecating > > >>>>>> LOCAL > > >>>>>>>>>> caches. > > >>>>>>>>>>> I just want to know why. > > >>>>>>>>>>> > > >>>>>>>>>>> D. > > >>>>>>>>>>> > > >>>>>>>>>>> On Wed, Jul 25, 2018 at 10:55 AM, Vladimir Ozerov < > > >>>>>>>>> voze...@gridgain.com> > > >>>>>>>>>>> wrote: > > >>>>>>>>>>> > > >>>>>>>>>>>> Dima, > > >>>>>>>>>>>> > > >>>>>>>>>>>> LOCAL cache adds very little value to the product. It > > >>>> doesn't > > >>>>>>>> support > > >>>>>>>>>>>> cross-cache transactions, consumes a lot of memory, > > >> much > > >>>> slower > > >>>>>>>> than > > >>>>>>>>>> any > > >>>>>>>>>>>> widely-used concurrent hash map. Let's go the same way > > >> as > > >>>> Java > > >>>>>> - > > >>>>>>>> mark > > >>>>>>>>>>> LOCAL > > >>>>>>>>>>>> cache as "deprecated for removal", and then remove it > > >> in > > >>>> 3.0. > > >>>>>>>>>>>> > > >>>>>>>>>>>> On Wed, Jul 25, 2018 at 12:10 PM Dmitrii Ryabov < > > >>>>>>>>> somefire...@gmail.com > > >>>>>>>>>>> > > >>>>>>>>>>>> wrote: > > >>>>>>>>>>>> > > >>>>>>>>>>>>> +1 to make LOCAL as filtered PARTITIONED cache. I > > >> think > > >>>> it > > >>>>>>> would > > >>>>>>>> be > > >>>>>>>>>>> much > > >>>>>>>>>>>>> easier and faster than fixing all bugs. > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> 2018-07-25 11:51 GMT+03:00 Dmitriy Setrakyan < > > >>>>>>>>> dsetrak...@apache.org > > >>>>>>>>>>> : > > >>>>>>>>>>>>> > > >>>>>>>>>>>>>> I would stay away from deprecating such huge > > >> pieces as > > >>>> a > > >>>>>>> whole > > >>>>>>>>>> LOCAL > > >>>>>>>>>>>>> cache. > > >>>>>>>>>>>>>> In retrospect, we should probably not even have > > >> LOCAL > > >>>>>> caches, > > >>>>>>>> but > > >>>>>>>>>>> now I > > >>>>>>>>>>>>> am > > >>>>>>>>>>>>>> certain that it is used by many users. > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>> I would do one of the following, whichever one is > > >>>> easier: > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>> - Fix the issues found with LOCAL caches, > > >> including > > >>>>>>>>> persistence > > >>>>>>>>>>>>> support > > >>>>>>>>>>>>>> - Implement LOCAL caches as PARTITIONED caches > > >> over > > >>>> the > > >>>>>>>> local > > >>>>>>>>>>> node. > > >>>>>>>>>>>> In > > >>>>>>>>>>>>>> this case, we would have to hide any > > >>>>>> distribution-related > > >>>>>>>>> config > > >>>>>>>>>>>> from > > >>>>>>>>>>>>>> users, like affinity function, for example. > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>> D. > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>> On Wed, Jul 25, 2018 at 9:05 AM, Valentin > > >> Kulichenko < > > >>>>>>>>>>>>>> valentin.kuliche...@gmail.com> wrote: > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>>> It sounds like the main drawback of LOCAL cache > > >> is > > >>>> that > > >>>>>>> it's > > >>>>>>>>>>>>> implemented > > >>>>>>>>>>>>>>> separately and therefore has to be maintained > > >>>> separately. > > >>>>>>> If > > >>>>>>>>>> that's > > >>>>>>>>>>>> the > > >>>>>>>>>>>>>>> only issue, why not keep LOCAL cache mode on > > >> public > > >>>> API, > > >>>>>>> but > > >>>>>>>>>>>> implement > > >>>>>>>>>>>>> it > > >>>>>>>>>>>>>>> as a PARTITIONED cache with a node filter > > >> forcefully > > >>>> set? > > >>>>>>>>> That's > > >>>>>>>>>>>>> similar > > >>>>>>>>>>>>>> to > > >>>>>>>>>>>>>>> what we do with REPLICATED caches which are > > >> actually > > >>>>>>>>> PARTITIONED > > >>>>>>>>>>> with > > >>>>>>>>>>>>>>> infinite number of backups. > > >>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>> This way we fix the issues described by Stan and > > >>>> don't > > >>>>>> have > > >>>>>>>> to > > >>>>>>>>>>>>> deprecate > > >>>>>>>>>>>>>>> anything. > > >>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>> -Val > > >>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>> On Wed, Jul 25, 2018 at 12:53 AM Stanislav > > >> Lukyanov < > > >>>>>>>>>>>>>>> stanlukya...@gmail.com> > > >>>>>>>>>>>>>>> wrote: > > >>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>> Hi Igniters, > > >>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>> I’d like to start a discussion about the > > >>>> deprecation of > > >>>>>>> the > > >>>>>>>>>> LOCAL > > >>>>>>>>>>>>>> caches. > > >>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>> LOCAL caches are an edge-case functionality > > >>>>>>>>>>>>>>>> I haven’t done any formal analysis, but from my > > >>>>>>> experience > > >>>>>>>>>> LOCAL > > >>>>>>>>>>>>> caches > > >>>>>>>>>>>>>>>> are needed very rarely, if ever. > > >>>>>>>>>>>>>>>> I think most usages of LOCAL caches I’ve seen > > >> were > > >>>>>>> misuses: > > >>>>>>>>> the > > >>>>>>>>>>>> users > > >>>>>>>>>>>>>>>> actually needed a simple HashMap, or an actual > > >>>>>>> PARTITIONED > > >>>>>>>>>> cache. > > >>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>> LOCAL caches are easy to implement on top of > > >>>>>> PARTITIONED > > >>>>>>>>>>>>>>>> If one requires a LOCAL cache (which is itself > > >>>>>>>> questionable, > > >>>>>>>>> as > > >>>>>>>>>>>>>> discussed > > >>>>>>>>>>>>>>>> above) it is quite easy to implement one on > > >> top of > > >>>>>>>>> PARTITIONED > > >>>>>>>>>>>> cache. > > >>>>>>>>>>>>>>>> A node filter of form `node -> node.id > > >>>>>>>>> ().equals(localNodeId)` > > >>>>>>>>>> is > > >>>>>>>>>>>>>> enough > > >>>>>>>>>>>>>>>> to make the cache to be stored on the node that > > >>>> created > > >>>>>>> it. > > >>>>>>>>>>>>>>>> Locality of access to the cache (i.e. making it > > >>>>>>> unavailable > > >>>>>>>>>> from > > >>>>>>>>>>>>> other > > >>>>>>>>>>>>>>>> nodes) can be achieved on the application > > >> level. > > >>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>> LOCAL caches are hard to maintain > > >>>>>>>>>>>>>>>> A quick look at the open issues mentioning > > >> “local > > >>>>>> cache” > > >>>>>>>>>> suggests > > >>>>>>>>>>>>> that > > >>>>>>>>>>>>>>>> this is a corner case for implementation of > > >> many > > >>>> Ignite > > >>>>>>>>>> features: > > >>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>> > > >>>>>> https://issues.apache.org/jira/issues/?jql=text%20~%20% > > >>>>>>>>>>>>>>> > > >> 22local%20cache%22%20and%20%20project%20%3D%20IGNITE% > > >>>>>>>>>>>>>>> 20and%20status%20%3D%20open > > >>>>>>>>>>>>>>>> In particular, a recent SO question brought up > > >> the > > >>>> fact > > >>>>>>>> that > > >>>>>>>>>>> LOCAL > > >>>>>>>>>>>>>> caches > > >>>>>>>>>>>>>>>> don’t support native persistence: > > >>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>> > > >>>> https://stackoverflow.com/questions/51511892/how-to- > > >>>>>>>>>>>>>>> > > >> configure-persistent-storage-for-apache-ignite-cache > > >>>>>>>>>>>>>>>> Having to ask ourselves “how does it play with > > >>>> LOCAL > > >>>>>>>> caches” > > >>>>>>>>>>> every > > >>>>>>>>>>>>> time > > >>>>>>>>>>>>>>> we > > >>>>>>>>>>>>>>>> write any code in Ignite seems way to much for > > >> the > > >>>>>>> benefits > > >>>>>>>>> we > > >>>>>>>>>>> gain > > >>>>>>>>>>>>>> from > > >>>>>>>>>>>>>>> it. > > >>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>> Proposal > > >>>>>>>>>>>>>>>> Let’s deprecate LOCAL caches in 2.x and remove > > >>>> them in > > >>>>>>> 3.0. > > >>>>>>>>>>>>>>>> As a part of deprecation let’s do the > > >> following: > > >>>>>>>>>>>>>>>> - Put @Deprecated on the CacheMode.LOCAL > > >>>>>>>>>>>>>>>> - Print a warning every time a LOCAL cache is > > >>>> created > > >>>>>>>>>>>>>>>> - Remove all mentions of LOCAL caches from > > >>>> readme.io, > > >>>>>> if > > >>>>>>>>> any, > > >>>>>>>>>>>> except > > >>>>>>>>>>>>>> for > > >>>>>>>>>>>>>>>> the page about cache modes > > >>>>>>>>>>>>>>>> - On the page about cache modes explain that > > >> LOCAL > > >>>> is > > >>>>>>>>>> deprecated > > >>>>>>>>>>>> and > > >>>>>>>>>>>>>> can > > >>>>>>>>>>>>>>>> be replaced with a PARTITIONED cache with a > > >> node > > >>>> filter > > >>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>>> Thanks, > > >>>>>>>>>>>>>>>> Stan > > >>>>>>>>>>>>>>>> > > >>>>>>>>>>>>>>> > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>> > > >>>>>>>>>>>> > > >>>>>>>>>>> > > >>>>>>>>>> > > >>>>>>>>> > > >>>>>>>> > > >>>>>>> > > >>>>>> > > >>>> > > >>> > > >>> > > >>> -- > > >>> Sincerely yours, Ivan Daschinskiy > > >> > > > > > > > > > -- > > > Sincerely yours, Ivan Daschinskiy > > > > > > -- > Sincerely yours, Ivan Daschinskiy >
