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From ALEKSEY KUZNETSOV <alkuznetsov...@gmail.com>
Subject Re: distributed transaction of non-single coordinator
Date Fri, 30 Jun 2017 16:14:43 GMT
Thanks! Do you think all test scenarios results, presented in table(in
ticket comments) , are acceptable ?

пт, 30 июн. 2017 г., 18:28 Yakov Zhdanov <yzhdanov@gridgain.com>:

> Alex, I have commented in the ticket. Please take a look.
>
> Thanks!
> --
> Yakov Zhdanov, Director R&D
> *GridGain Systems*
> www.gridgain.com
>
> 2017-06-29 17:27 GMT+03:00 ALEKSEY KUZNETSOV <alkuznetsov.sb@gmail.com>:
>
> > I've attached HangTest. I suppose it should not hang, am i right ?
> >
> > чт, 29 июн. 2017 г. в 14:54, ALEKSEY KUZNETSOV <alkuznetsov.sb@gmail.com
> >:
> >
> > > Igntrs.
> > > Im rewieving all usages of threadId of
> > > transaction.(IgniteTxAdapter#threadID). What is the point of usage
> > threadId
> > > in mvcc entry ?
> > >
> > > пн, 3 апр. 2017 г. в 9:47, ALEKSEY KUZNETSOV <alkuznetsov.sb@gmail.com
> >:
> > >
> > >> so what do u think on my idea?
> > >>
> > >> пт, 31 Мар 2017 г., 11:05 ALEKSEY KUZNETSOV <alkuznetsov.sb@gmail.com
> >:
> > >>
> > >>> sorry for misleading you. We planned to support multi-node
> > transactions,
> > >>> but failed.
> > >>>
> > >>> пт, 31 мар. 2017 г. в 10:51, Alexey Goncharuk <
> > >>> alexey.goncharuk@gmail.com>:
> > >>>
> > >>> Well, now the scenario is more clear, but it has nothing to do with
> > >>> multiple coordinators :) Let me think a little bit about it.
> > >>>
> > >>> 2017-03-31 9:53 GMT+03:00 ALEKSEY KUZNETSOV <
> alkuznetsov.sb@gmail.com
> > >:
> > >>>
> > >>> > so what do u think on the issue ?
> > >>> >
> > >>> > чт, 30 Мар 2017 г., 17:49 ALEKSEY KUZNETSOV <
> > alkuznetsov.sb@gmail.com
> > >>> >:
> > >>> >
> > >>> > > Hi ! Thanks for help. I've created ticket :
> > >>> > > https://issues.apache.org/jira/browse/IGNITE-4887
> > >>> > > and a commit :
> > >>> > >
> > >>>
> https://github.com/voipp/ignite/commit/aa3487bd9c203394f534c605f84e06
> > >>> > 436b638e5c
> > >>> > > We really need this feature
> > >>> > >
> > >>> > > чт, 30 мар. 2017 г. в 11:31, Alexey Goncharuk <
> > >>> > alexey.goncharuk@gmail.com
> > >>> > > >:
> > >>> > >
> > >>> > > Aleksey,
> > >>> > >
> > >>> > > I doubt your approach works as expected. Current transaction
> > recovery
> > >>> > > protocol heavily relies on the originating node ID in its
> internal
> > >>> logic.
> > >>> > > For example, currently a transaction will be rolled back if you
> > want
> > >>> to
> > >>> > > transfer a transaction ownership to another node and original tx
> > >>> owner
> > >>> > > fails. An attempt to commit such a transaction on another node
> may
> > >>> fail
> > >>> > > with all sorts of assertions. After transaction ownership
> changed,
> > >>> you
> > >>> > need
> > >>> > > to notify all current transaction participants about this change,
> > >>> and it
> > >>> > > should also be done failover-safe, let alone that you did not add
> > any
> > >>> > tests
> > >>> > > for these cases.
> > >>> > >
> > >>> > > I back Denis here. Please create a ticket first and come up with
> > >>> clear
> > >>> > > use-cases, API and protocol changes design. It is hard to reason
> > >>> about
> > >>> > the
> > >>> > > changes you've made when we do not even understand why you are
> > making
> > >>> > these
> > >>> > > changes and how they are supposed to work.
> > >>> > >
> > >>> > > --AG
> > >>> > >
> > >>> > > 2017-03-30 10:43 GMT+03:00 ALEKSEY KUZNETSOV <
> > >>> alkuznetsov.sb@gmail.com>:
> > >>> > >
> > >>> > > > So, what do u think on my idea ?
> > >>> > > >
> > >>> > > > ср, 29 мар. 2017 г. в 10:35, ALEKSEY KUZNETSOV <
> > >>> > alkuznetsov.sb@gmail.com
> > >>> > > >:
> > >>> > > >
> > >>> > > > > Hi! No, i dont have ticket for this.
> > >>> > > > > In the ticket i have implemented methods that change
> > transaction
> > >>> > status
> > >>> > > > to
> > >>> > > > > STOP, thus letting it to commit transaction in another
> thread.
> > In
> > >>> > > another
> > >>> > > > > thread you r going to restart transaction in order to commit
> > it.
> > >>> > > > > The mechanism behind it is obvious : we change thread id to
> > >>> newer one
> > >>> > > in
> > >>> > > > > ThreadMap, and make use of serialization of txState,
> > transactions
> > >>> > > itself
> > >>> > > > to
> > >>> > > > > transfer them into another thread.
> > >>> > > > >
> > >>> > > > >
> > >>> > > > > вт, 28 мар. 2017 г. в 20:15, Denis Magda <dmagda@apache.org
> >:
> > >>> > > > >
> > >>> > > > > Aleksey,
> > >>> > > > >
> > >>> > > > > Do you have a ticket for this? Could you briefly list what
> > >>> exactly
> > >>> > was
> > >>> > > > > done and how the things work.
> > >>> > > > >
> > >>> > > > > —
> > >>> > > > > Denis
> > >>> > > > >
> > >>> > > > > > On Mar 28, 2017, at 8:32 AM, ALEKSEY KUZNETSOV <
> > >>> > > > alkuznetsov.sb@gmail.com>
> > >>> > > > > wrote:
> > >>> > > > > >
> > >>> > > > > > Hi, Igniters! I 've made implementation of transactions of
> > >>> > non-single
> > >>> > > > > > coordinator. Here you can start transaction in one thread
> and
> > >>> > commit
> > >>> > > it
> > >>> > > > > in
> > >>> > > > > > another thread.
> > >>> > > > > > Take a look on it. Give your thoughts on it.
> > >>> > > > > >
> > >>> > > > > >
> > >>> > > > > https://github.com/voipp/ignite/pull/10/commits/
> > >>> > > > 3a3d90aa6ac84f125e4c3ce4ced4f269a695ef45
> > >>> > > > > >
> > >>> > > > > > пт, 17 мар. 2017 г. в 19:26, Sergi Vladykin <
> > >>> > > sergi.vladykin@gmail.com
> > >>> > > > >:
> > >>> > > > > >
> > >>> > > > > >> You know better, go ahead! :)
> > >>> > > > > >>
> > >>> > > > > >> Sergi
> > >>> > > > > >>
> > >>> > > > > >> 2017-03-17 16:16 GMT+03:00 ALEKSEY KUZNETSOV <
> > >>> > > > alkuznetsov.sb@gmail.com
> > >>> > > > > >:
> > >>> > > > > >>
> > >>> > > > > >>> we've discovered several problems regarding your
> > >>> "accumulation"
> > >>> > > > > >>> approach.These are
> > >>> > > > > >>>
> > >>> > > > > >>>   1. perfomance issues when transfering data from
> temporary
> > >>> cache
> > >>> > > to
> > >>> > > > > >>>   permanent one. Keep in mind big deal of concurent
> > >>> transactions
> > >>> > in
> > >>> > > > > >>> Service
> > >>> > > > > >>>   commiter
> > >>> > > > > >>>   2. extreme memory load when keeping temporary cache in
> > >>> memory
> > >>> > > > > >>>   3. As long as user is not acquainted with ignite,
> working
> > >>> with
> > >>> > > > cache
> > >>> > > > > >>>   must be transparent for him. Keep this in mind. User's
> > >>> node can
> > >>> > > > > >> evaluate
> > >>> > > > > >>>   logic with no transaction at all, so we should deal
> with
> > >>> both
> > >>> > > types
> > >>> > > > > of
> > >>> > > > > >>>   execution flow : transactional and
> > >>> non-transactional.Another
> > >>> > one
> > >>> > > > > >>> problem is
> > >>> > > > > >>>   transaction id support at the user node. We would have
> > >>> handled
> > >>> > > all
> > >>> > > > > >> this
> > >>> > > > > >>>   issues and many more.
> > >>> > > > > >>>   4. we cannot pessimistically lock entity.
> > >>> > > > > >>>
> > >>> > > > > >>> As a result, we decided to move on building distributed
> > >>> > > transaction.
> > >>> > > > We
> > >>> > > > > >> put
> > >>> > > > > >>> aside your "accumulation" approach until we realize how
> to
> > >>> solve
> > >>> > > > > >>> difficulties above .
> > >>> > > > > >>>
> > >>> > > > > >>> чт, 16 мар. 2017 г. в 16:56, Sergi Vladykin <
> > >>> > > > sergi.vladykin@gmail.com
> > >>> > > > > >:
> > >>> > > > > >>>
> > >>> > > > > >>>> The problem "How to run millions of entities, and
> millions
> > >>> of
> > >>> > > > > >> operations
> > >>> > > > > >>> on
> > >>> > > > > >>>> a single Pentium3" is out of scope here. Do the math,
> plan
> > >>> > > capacity
> > >>> > > > > >>>> reasonably.
> > >>> > > > > >>>>
> > >>> > > > > >>>> Sergi
> > >>> > > > > >>>>
> > >>> > > > > >>>> 2017-03-16 15:54 GMT+03:00 ALEKSEY KUZNETSOV <
> > >>> > > > > alkuznetsov.sb@gmail.com
> > >>> > > > > >>> :
> > >>> > > > > >>>>
> > >>> > > > > >>>>> hmm, If we have millions of entities, and millions of
> > >>> > operations,
> > >>> > > > > >> would
> > >>> > > > > >>>> not
> > >>> > > > > >>>>> this approache lead to memory overflow and perfomance
> > >>> > degradation
> > >>> > > > > >>>>>
> > >>> > > > > >>>>> чт, 16 мар. 2017 г. в 15:42, Sergi Vladykin <
> > >>> > > > > >> sergi.vladykin@gmail.com
> > >>> > > > > >>>> :
> > >>> > > > > >>>>>
> > >>> > > > > >>>>>> 1. Actually you have to check versions on all the
> values
> > >>> you
> > >>> > > have
> > >>> > > > > >>> read
> > >>> > > > > >>>>>> during the tx.
> > >>> > > > > >>>>>>
> > >>> > > > > >>>>>> For example if we have [k1 => v1, k2 => v2] and do:
> > >>> > > > > >>>>>>
> > >>> > > > > >>>>>> put(k1, get(k2) + 5)
> > >>> > > > > >>>>>>
> > >>> > > > > >>>>>> We have to remember the version for k2. This logic can
> > be
> > >>> > > > > >> relatively
> > >>> > > > > >>>>> easily
> > >>> > > > > >>>>>> encapsulated in a framework atop of Ignite. You need
> to
> > >>> > > implement
> > >>> > > > > >> one
> > >>> > > > > >>>> to
> > >>> > > > > >>>>>> make all this stuff usable.
> > >>> > > > > >>>>>>
> > >>> > > > > >>>>>> 2. I suggest to avoid any locking here, because you
> > easily
> > >>> > will
> > >>> > > > end
> > >>> > > > > >>> up
> > >>> > > > > >>>>> with
> > >>> > > > > >>>>>> deadlocks. If you do not have too frequent updates for
> > >>> your
> > >>> > > keys,
> > >>> > > > > >>>>>> optimistic approach will work just fine.
> > >>> > > > > >>>>>>
> > >>> > > > > >>>>>> Theoretically in the Committer Service you can start a
> > >>> thread
> > >>> > > for
> > >>> > > > > >> the
> > >>> > > > > >>>>>> lifetime of the whole distributed transaction, take a
> > >>> lock on
> > >>> > > the
> > >>> > > > > >> key
> > >>> > > > > >>>>> using
> > >>> > > > > >>>>>> IgniteCache.lock(K key) before executing any Services,
> > >>> wait
> > >>> > for
> > >>> > > > all
> > >>> > > > > >>> the
> > >>> > > > > >>>>>> services to complete, execute optimistic commit in the
> > >>> same
> > >>> > > thread
> > >>> > > > > >>>> while
> > >>> > > > > >>>>>> keeping this lock and then release it. Notice that all
> > the
> > >>> > > Ignite
> > >>> > > > > >>>>>> transactions inside of all Services must be optimistic
> > >>> here to
> > >>> > > be
> > >>> > > > > >>> able
> > >>> > > > > >>>> to
> > >>> > > > > >>>>>> read this locked key.
> > >>> > > > > >>>>>>
> > >>> > > > > >>>>>> But again I do not recommend you using this approach
> > >>> until you
> > >>> > > > > >> have a
> > >>> > > > > >>>>>> reliable deadlock avoidance scheme.
> > >>> > > > > >>>>>>
> > >>> > > > > >>>>>> Sergi
> > >>> > > > > >>>>>>
> > >>> > > > > >>>>>>
> > >>> > > > > >>>>>>
> > >>> > > > > >>>>>>
> > >>> > > > > >>>>>>
> > >>> > > > > >>>>>>
> > >>> > > > > >>>>>>
> > >>> > > > > >>>>>> 2017-03-16 12:53 GMT+03:00 ALEKSEY KUZNETSOV <
> > >>> > > > > >>> alkuznetsov.sb@gmail.com
> > >>> > > > > >>>>> :
> > >>> > > > > >>>>>>
> > >>> > > > > >>>>>>> Yeah, now i got it.
> > >>> > > > > >>>>>>> There are some doubts on this approach
> > >>> > > > > >>>>>>> 1) During optimistic commit phase, when you assure no
> > one
> > >>> > > altered
> > >>> > > > > >>> the
> > >>> > > > > >>>>>>> original values, you must check versions of other
> > >>> dependent
> > >>> > > keys.
> > >>> > > > > >>> How
> > >>> > > > > >>>>>> could
> > >>> > > > > >>>>>>> we obtain those keys(in an automative manner, of
> > course)
> > >>> ?
> > >>> > > > > >>>>>>> 2) How could we lock a key before some Service A
> > >>> introduce
> > >>> > > > > >> changes?
> > >>> > > > > >>>> So
> > >>> > > > > >>>>> no
> > >>> > > > > >>>>>>> other service is allowed to change this
> key-value?(sort
> > >>> of
> > >>> > > > > >>>> pessimistic
> > >>> > > > > >>>>>>> blocking)
> > >>> > > > > >>>>>>> May be you know some implementations of such
> approach ?
> > >>> > > > > >>>>>>>
> > >>> > > > > >>>>>>> ср, 15 мар. 2017 г. в 17:54, ALEKSEY KUZNETSOV <
> > >>> > > > > >>>>> alkuznetsov.sb@gmail.com
> > >>> > > > > >>>>>>> :
> > >>> > > > > >>>>>>>
> > >>> > > > > >>>>>>>> Thank you very much for help.  I will answer later.
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>> ср, 15 мар. 2017 г. в 17:39, Sergi Vladykin <
> > >>> > > > > >>>>> sergi.vladykin@gmail.com
> > >>> > > > > >>>>>>> :
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>> All the services do not update key in place, but
> only
> > >>> > generate
> > >>> > > > > >>> new
> > >>> > > > > >>>>> keys
> > >>> > > > > >>>>>>>> augmented by otx and store the updated value in the
> > same
> > >>> > cache
> > >>> > > > > >> +
> > >>> > > > > >>>>>> remember
> > >>> > > > > >>>>>>>> the keys and versions participating in the
> transaction
> > >>> in
> > >>> > some
> > >>> > > > > >>>>> separate
> > >>> > > > > >>>>>>>> atomic cache.
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>> Follow this sequence of changes applied to cache
> > >>> contents by
> > >>> > > > > >> each
> > >>> > > > > >>>>>>> Service:
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>> Initial cache contents:
> > >>> > > > > >>>>>>>>            [k1 => v1]
> > >>> > > > > >>>>>>>>            [k2 => v2]
> > >>> > > > > >>>>>>>>            [k3 => v3]
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>> Cache contents after Service A:
> > >>> > > > > >>>>>>>>            [k1 => v1]
> > >>> > > > > >>>>>>>>            [k2 => v2]
> > >>> > > > > >>>>>>>>            [k3 => v3]
> > >>> > > > > >>>>>>>>            [k1x => v1a]
> > >>> > > > > >>>>>>>>            [k2x => v2a]
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>>         + [x => (k1 -> ver1, k2 -> ver2)] in some
> > >>> separate
> > >>> > > > > >>> atomic
> > >>> > > > > >>>>>> cache
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>> Cache contents after Service B:
> > >>> > > > > >>>>>>>>            [k1 => v1]
> > >>> > > > > >>>>>>>>            [k2 => v2]
> > >>> > > > > >>>>>>>>            [k3 => v3]
> > >>> > > > > >>>>>>>>            [k1x => v1a]
> > >>> > > > > >>>>>>>>            [k2x => v2ab]
> > >>> > > > > >>>>>>>>            [k3x => v3b]
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>>        + [x => (k1 -> ver1, k2 -> ver2, k3 -> ver3)]
> > in
> > >>> some
> > >>> > > > > >>>>> separate
> > >>> > > > > >>>>>>>> atomic cache
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>> Finally the Committer Service takes this map of
> > updated
> > >>> keys
> > >>> > > > > >> and
> > >>> > > > > >>>>> their
> > >>> > > > > >>>>>>>> versions from some separate atomic cache, starts
> > Ignite
> > >>> > > > > >>> transaction
> > >>> > > > > >>>>> and
> > >>> > > > > >>>>>>>> replaces all the values for k* keys to values taken
> > >>> from k*x
> > >>> > > > > >>> keys.
> > >>> > > > > >>>>> The
> > >>> > > > > >>>>>>>> successful result must be the following:
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>>            [k1 => v1a]
> > >>> > > > > >>>>>>>>            [k2 => v2ab]
> > >>> > > > > >>>>>>>>            [k3 => v3b]
> > >>> > > > > >>>>>>>>            [k1x => v1a]
> > >>> > > > > >>>>>>>>            [k2x => v2ab]
> > >>> > > > > >>>>>>>>            [k3x => v3b]
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>>        + [x => (k1 -> ver1, k2 -> ver2, k3 -> ver3)]
> > in
> > >>> some
> > >>> > > > > >>>>> separate
> > >>> > > > > >>>>>>>> atomic cache
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>> But Committer Service also has to check that no one
> > >>> updated
> > >>> > > the
> > >>> > > > > >>>>>> original
> > >>> > > > > >>>>>>>> values before us, because otherwise we can not give
> > any
> > >>> > > > > >>>>> serializability
> > >>> > > > > >>>>>>>> guarantee for these distributed transactions. Here
> we
> > >>> may
> > >>> > need
> > >>> > > > > >> to
> > >>> > > > > >>>>> check
> > >>> > > > > >>>>>>> not
> > >>> > > > > >>>>>>>> only versions of the updated keys, but also versions
> > of
> > >>> any
> > >>> > > > > >> other
> > >>> > > > > >>>>> keys
> > >>> > > > > >>>>>>> end
> > >>> > > > > >>>>>>>> result depends on.
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>> After that Committer Service has to do a cleanup
> (may
> > be
> > >>> > > > > >> outside
> > >>> > > > > >>> of
> > >>> > > > > >>>>> the
> > >>> > > > > >>>>>>>> committing tx) to come to the following final state:
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>>            [k1 => v1a]
> > >>> > > > > >>>>>>>>            [k2 => v2ab]
> > >>> > > > > >>>>>>>>            [k3 => v3b]
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>> Makes sense?
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>> Sergi
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>> 2017-03-15 16:54 GMT+03:00 ALEKSEY KUZNETSOV <
> > >>> > > > > >>>>> alkuznetsov.sb@gmail.com
> > >>> > > > > >>>>>>> :
> > >>> > > > > >>>>>>>>
> > >>> > > > > >>>>>>>>>   - what do u mean by saying "
> > >>> > > > > >>>>>>>>> *in a single transaction checks value versions for
> > all
> > >>> the
> > >>> > > > > >> old
> > >>> > > > > >>>>> values
> > >>> > > > > >>>>>>>>>    and replaces them with calculated new ones *"?
> > Every
> > >>> > time
> > >>> > > > > >>> you
> > >>> > > > > >>>>>>> change
> > >>> > > > > >>>>>>>>>   value(in some service), you store it to *some
> > special
> > >>> > > > > >> atomic
> > >>> > > > > >>>>>> cache*
> > >>> > > > > >>>>>>> ,
> > >>> > > > > >>>>>>>> so
> > >>> > > > > >>>>>>>>>   when all services ceased working, Service
> commiter
> > >>> got a
> > >>> > > > > >>>> values
> > >>> > > > > >>>>>> with
> > >>> > > > > >>>>>>>> the
> > >>> > > > > >>>>>>>>>   last versions.
> > >>> > > > > >>>>>>>>>   - After "*does cleanup of temporary keys and
> > values*"
> > >>> > > > > >>> Service
> > >>> > > > > >>>>>>> commiter
> > >>> > > > > >>>>>>>>>   persists them into permanent store, isn't it ?
> > >>> > > > > >>>>>>>>>   - I cant grasp your though, you say "*in case of
> > >>> version
> > >>> > > > > >>>>> mismatch
> > >>> > > > > >>>>>> or
> > >>> > > > > >>>>>>>> TX
> > >>> > > > > >>>>>>>>>   timeout just rollbacks*". But what versions would
> > it
> > >>> > > > > >> match?
> > >>> > > > > >>>>>>>>>
> > >>> > > > > >>>>>>>>>
> > >>> > > > > >>>>>>>>> ср, 15 мар. 2017 г. в 15:34, Sergi Vladykin <
> > >>> > > > > >>>>>> sergi.vladykin@gmail.com
> > >>> > > > > >>>>>>>> :
> > >>> > > > > >>>>>>>>>
> > >>> > > > > >>>>>>>>>> Ok, here is what you actually need to implement at
> > the
> > >>> > > > > >>>>> application
> > >>> > > > > >>>>>>>> level.
> > >>> > > > > >>>>>>>>>>
> > >>> > > > > >>>>>>>>>> Lets say we have to call 2 services in the
> following
> > >>> > order:
> > >>> > > > > >>>>>>>>>> - Service A: wants to update keys [k1 => v1,   k2
> =>
> > >>> v2]
> > >>> > > > > >> to
> > >>> > > > > >>>>> [k1
> > >>> > > > > >>>>>> =>
> > >>> > > > > >>>>>>>>> v1a,
> > >>> > > > > >>>>>>>>>>  k2 => v2a]
> > >>> > > > > >>>>>>>>>> - Service B: wants to update keys [k2 => v2a, k3
> =>
> > >>> v3]
> > >>> > > > > >> to
> > >>> > > > > >>>> [k2
> > >>> > > > > >>>>>> =>
> > >>> > > > > >>>>>>>>> v2ab,
> > >>> > > > > >>>>>>>>>> k3 => v3b]
> > >>> > > > > >>>>>>>>>>
> > >>> > > > > >>>>>>>>>> The change
> > >>> > > > > >>>>>>>>>>    from [ k1 => v1,   k2 => v2,     k3 => v3   ]
> > >>> > > > > >>>>>>>>>>    to     [ k1 => v1a, k2 => v2ab, k3 => v3b ]
> > >>> > > > > >>>>>>>>>> must happen in a single transaction.
> > >>> > > > > >>>>>>>>>>
> > >>> > > > > >>>>>>>>>>
> > >>> > > > > >>>>>>>>>> Optimistic protocol to solve this:
> > >>> > > > > >>>>>>>>>>
> > >>> > > > > >>>>>>>>>> Each cache key must have a field `otx`, which is a
> > >>> unique
> > >>> > > > > >>>>>>> orchestrator
> > >>> > > > > >>>>>>>> TX
> > >>> > > > > >>>>>>>>>> identifier - it must be a parameter passed to all
> > the
> > >>> > > > > >>> services.
> > >>> > > > > >>>>> If
> > >>> > > > > >>>>>>>> `otx`
> > >>> > > > > >>>>>>>>> is
> > >>> > > > > >>>>>>>>>> set to some value it means that it is an
> > intermediate
> > >>> key
> > >>> > > > > >> and
> > >>> > > > > >>>> is
> > >>> > > > > >>>>>>>> visible
> > >>> > > > > >>>>>>>>>> only inside of some transaction, for the finalized
> > key
> > >>> > > > > >> `otx`
> > >>> > > > > >>>> must
> > >>> > > > > >>>>>> be
> > >>> > > > > >>>>>>>>> null -
> > >>> > > > > >>>>>>>>>> it means the key is committed and visible for
> > >>> everyone.
> > >>> > > > > >>>>>>>>>>
> > >>> > > > > >>>>>>>>>> Each cache value must have a field `ver` which is
> a
> > >>> > version
> > >>> > > > > >>> of
> > >>> > > > > >>>>> that
> > >>> > > > > >>>>>>>>> value.
> > >>> > > > > >>>>>>>>>>
> > >>> > > > > >>>>>>>>>> For both fields (`otx` and `ver`) the safest way
> is
> > >>> to use
> > >>> > > > > >>>> UUID.
> > >>> > > > > >>>>>>>>>>
> > >>> > > > > >>>>>>>>>> Workflow is the following:
> > >>> > > > > >>>>>>>>>>
> > >>> > > > > >>>>>>>>>> Orchestrator starts the distributed transaction
> with
> > >>> `otx`
> > >>> > > > > >> =
> > >>> > > > > >>> x
> > >>> > > > > >>>>> and
> > >>> > > > > >>>>>>>> passes
> > >>> > > > > >>>>>>>>>> this parameter to all the services.
> > >>> > > > > >>>>>>>>>>
> > >>> > > > > >>>>>>>>>> Service A:
> > >>> > > > > >>>>>>>>>> - does some computations
> > >>> > > > > >>>>>>>>>> - stores [k1x => v1a, k2x => v2a]  with TTL = Za
> > >>> > > > > >>>>>>>>>>      where
> > >>> > > > > >>>>>>>>>>          Za - left time from max Orchestrator TX
> > >>> duration
> > >>> > > > > >>>> after
> > >>> > > > > >>>>>>>> Service
> > >>> > > > > >>>>>>>>> A
> > >>> > > > > >>>>>>>>>> end
> > >>> > > > > >>>>>>>>>>          k1x, k2x - new temporary keys with field
> > >>> `otx` =
> > >>> > > > > >> x
> > >>> > > > > >>>>>>>>>>          v2a has updated version `ver`
> > >>> > > > > >>>>>>>>>> - returns a set of updated keys and all the old
> > >>> versions
> > >>> > > > > >> to
> > >>> > > > > >>>> the
> > >>> > > > > >>>>>>>>>> orchestrator
> > >>> > > > > >>>>>>>>>>       or just stores it in some special atomic
> cache
> > >>> like
> > >>> > > > > >>>>>>>>>>       [x => (k1 -> ver1, k2 -> ver2)] TTL = Za
> > >>> > > > > >>>>>>>>>>
> > >>> > > > > >>>>>>>>>> Service B:
> > >>> > > > > >>>>>>>>>> - retrieves the updated value k2x => v2a because
> it
> > >>> knows
> > >>> > > > > >>>> `otx`
> > >>> > > > > >>>>> =
> > >>> > > > > >>>>>> x
> > >>> > > > > >>>>>>>>>> - does computations
> > >>> > > > > >>>>>>>>>> - stores [k2x => v2ab, k3x => v3b] TTL = Zb
> > >>> > > > > >>>>>>>>>> - updates the set of updated keys like [x => (k1
> ->
> > >>> ver1,
> > >>> > > > > >> k2
> > >>> > > > > >>>> ->
> > >>> > > > > >>>>>>> ver2,
> > >>> > > > > >>>>>>>> k3
> > >>> > > > > >>>>>>>>>> -> ver3)] TTL = Zb
> > >>> > > > > >>>>>>>>>>
> > >>> > > > > >>>>>>>>>> Service Committer (may be embedded into
> > Orchestrator):
> > >>> > > > > >>>>>>>>>> - takes all the updated keys and versions for
> `otx`
> > =
> > >>> x
> > >>> > > > > >>>>>>>>>>       [x => (k1 -> ver1, k2 -> ver2, k3 -> ver3)]
> > >>> > > > > >>>>>>>>>> - in a single transaction checks value versions
> for
> > >>> all
> > >>> > > > > >> the
> > >>> > > > > >>>> old
> > >>> > > > > >>>>>>> values
> > >>> > > > > >>>>>>>>>>       and replaces them with calculated new ones
> > >>> > > > > >>>>>>>>>> - does cleanup of temporary keys and values
> > >>> > > > > >>>>>>>>>> - in case of version mismatch or TX timeout just
> > >>> rollbacks
> > >>> > > > > >>> and
> > >>> > > > > >>>>>>> signals
> > >>> > > > > >>>>>>>>>>        to Orchestrator to restart the job with new
> > >>> `otx`
> > >>> > > > > >>>>>>>>>>
> > >>> > > > > >>>>>>>>>> PROFIT!!
> > >>> > > > > >>>>>>>>>>
> > >>> > > > > >>>>>>>>>> This approach even allows you to run independent
> > >>> parts of
> > >>> > > > > >> the
> > >>> > > > > >>>>> graph
> > >>> > > > > >>>>>>> in
> > >>> > > > > >>>>>>>>>> parallel (with TX transfer you will always run
> only
> > >>> one at
> > >>> > > > > >> a
> > >>> > > > > >>>>> time).
> > >>> > > > > >>>>>>>> Also
> > >>> > > > > >>>>>>>>> it
> > >>> > > > > >>>>>>>>>> does not require inventing any special fault
> > tolerance
> > >>> > > > > >>> technics
> > >>> > > > > >>>>>>> because
> > >>> > > > > >>>>>>>>>> Ignite caches are already fault tolerant and all
> the
> > >>> > > > > >>>> intermediate
> > >>> > > > > >>>>>>>> results
> > >>> > > > > >>>>>>>>>> are virtually invisible and stored with TTL, thus
> in
> > >>> case
> > >>> > > > > >> of
> > >>> > > > > >>>> any
> > >>> > > > > >>>>>>> crash
> > >>> > > > > >>>>>>>>> you
> > >>> > > > > >>>>>>>>>> will not have inconsistent state or garbage.
> > >>> > > > > >>>>>>>>>>
> > >>> > > > > >>>>>>>>>> Sergi
> > >>> > > > > >>>>>>>>>>
> > >>> > > > > >>>>>>>>>>
> > >>> > > > > >>>>>>>>>> 2017-03-15 11:42 GMT+03:00 ALEKSEY KUZNETSOV <
> > >>> > > > > >>>>>>> alkuznetsov.sb@gmail.com
> > >>> > > > > >>>>>>>>> :
> > >>> > > > > >>>>>>>>>>
> > >>> > > > > >>>>>>>>>>> Okay, we are open for proposals on business
> task. I
> > >>> mean,
> > >>> > > > > >>> we
> > >>> > > > > >>>>> can
> > >>> > > > > >>>>>>> make
> > >>> > > > > >>>>>>>>> use
> > >>> > > > > >>>>>>>>>>> of some other thing, not distributed transaction.
> > Not
> > >>> > > > > >>>>> transaction
> > >>> > > > > >>>>>>>> yet.
> > >>> > > > > >>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>> ср, 15 мар. 2017 г. в 11:24, Vladimir Ozerov <
> > >>> > > > > >>>>>> vozerov@gridgain.com
> > >>> > > > > >>>>>>>> :
> > >>> > > > > >>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>> IMO the use case makes sense. However, as Sergi
> > >>> already
> > >>> > > > > >>>>>>> mentioned,
> > >>> > > > > >>>>>>>>> the
> > >>> > > > > >>>>>>>>>>>> problem is far more complex, than simply passing
> > TX
> > >>> > > > > >> state
> > >>> > > > > >>>>> over
> > >>> > > > > >>>>>> a
> > >>> > > > > >>>>>>>>> wire.
> > >>> > > > > >>>>>>>>>>> Most
> > >>> > > > > >>>>>>>>>>>> probably a kind of coordinator will be required
> > >>> still
> > >>> > > > > >> to
> > >>> > > > > >>>>> manage
> > >>> > > > > >>>>>>> all
> > >>> > > > > >>>>>>>>>> kinds
> > >>> > > > > >>>>>>>>>>>> of failures. This task should be started with
> > clean
> > >>> > > > > >>> design
> > >>> > > > > >>>>>>> proposal
> > >>> > > > > >>>>>>>>>>>> explaining how we handle all these concurrent
> > >>> events.
> > >>> > > > > >> And
> > >>> > > > > >>>>> only
> > >>> > > > > >>>>>>>> then,
> > >>> > > > > >>>>>>>>>> when
> > >>> > > > > >>>>>>>>>>>> we understand all implications, we should move
> to
> > >>> > > > > >>>> development
> > >>> > > > > >>>>>>>> stage.
> > >>> > > > > >>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>> On Wed, Mar 15, 2017 at 10:38 AM, ALEKSEY
> > KUZNETSOV
> > >>> <
> > >>> > > > > >>>>>>>>>>>> alkuznetsov.sb@gmail.com> wrote:
> > >>> > > > > >>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>> Right
> > >>> > > > > >>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>> ср, 15 мар. 2017 г. в 10:35, Sergi Vladykin <
> > >>> > > > > >>>>>>>>>> sergi.vladykin@gmail.com
> > >>> > > > > >>>>>>>>>>>> :
> > >>> > > > > >>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>> Good! Basically your orchestrator just takes
> > some
> > >>> > > > > >>>>>> predefined
> > >>> > > > > >>>>>>>>> graph
> > >>> > > > > >>>>>>>>>> of
> > >>> > > > > >>>>>>>>>>>>>> distributed services to be invoked, calls them
> > by
> > >>> > > > > >>> some
> > >>> > > > > >>>>> kind
> > >>> > > > > >>>>>>> of
> > >>> > > > > >>>>>>>>> RPC
> > >>> > > > > >>>>>>>>>>> and
> > >>> > > > > >>>>>>>>>>>>>> passes the needed parameters between them,
> > right?
> > >>> > > > > >>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>> Sergi
> > >>> > > > > >>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>> 2017-03-14 22:46 GMT+03:00 ALEKSEY KUZNETSOV <
> > >>> > > > > >>>>>>>>>>> alkuznetsov.sb@gmail.com
> > >>> > > > > >>>>>>>>>>>>> :
> > >>> > > > > >>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>> orchestrator is a custom thing. He is
> > responsible
> > >>> > > > > >>> for
> > >>> > > > > >>>>>>>> managing
> > >>> > > > > >>>>>>>>>>>> business
> > >>> > > > > >>>>>>>>>>>>>>> scenarios flows. Many nodes are involved in
> > >>> > > > > >>>> scenarios.
> > >>> > > > > >>>>>> They
> > >>> > > > > >>>>>>>>>>> exchange
> > >>> > > > > >>>>>>>>>>>>> data
> > >>> > > > > >>>>>>>>>>>>>>> and folow one another. If you acquinted with
> > BPMN
> > >>> > > > > >>>>>>> framework,
> > >>> > > > > >>>>>>>> so
> > >>> > > > > >>>>>>>>>>>>>>> orchestrator is like bpmn engine.
> > >>> > > > > >>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>> вт, 14 Мар 2017 г., 18:56 Sergi Vladykin <
> > >>> > > > > >>>>>>>>>> sergi.vladykin@gmail.com
> > >>> > > > > >>>>>>>>>>>> :
> > >>> > > > > >>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>> What is Orchestrator for you? Is it a thing
> > >>> > > > > >> from
> > >>> > > > > >>>>>>> Microsoft
> > >>> > > > > >>>>>>>> or
> > >>> > > > > >>>>>>>>>>> your
> > >>> > > > > >>>>>>>>>>>>>> custom
> > >>> > > > > >>>>>>>>>>>>>>>> in-house software?
> > >>> > > > > >>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>> Sergi
> > >>> > > > > >>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>> 2017-03-14 18:00 GMT+03:00 ALEKSEY
> KUZNETSOV <
> > >>> > > > > >>>>>>>>>>>>> alkuznetsov.sb@gmail.com
> > >>> > > > > >>>>>>>>>>>>>>> :
> > >>> > > > > >>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>> Fine. Let's say we've got multiple servers
> > >>> > > > > >>> which
> > >>> > > > > >>>>>>> fulfills
> > >>> > > > > >>>>>>>>>>> custom
> > >>> > > > > >>>>>>>>>>>>>> logic.
> > >>> > > > > >>>>>>>>>>>>>>>>> This servers compound oriented graph (BPMN
> > >>> > > > > >>>> process)
> > >>> > > > > >>>>>>> which
> > >>> > > > > >>>>>>>>>>>>> controlled
> > >>> > > > > >>>>>>>>>>>>>> by
> > >>> > > > > >>>>>>>>>>>>>>>>> Orchestrator.
> > >>> > > > > >>>>>>>>>>>>>>>>> For instance, *server1  *creates *variable
> A
> > >>> > > > > >>>> *with
> > >>> > > > > >>>>>>> value
> > >>> > > > > >>>>>>>> 1,
> > >>> > > > > >>>>>>>>>>>>> persists
> > >>> > > > > >>>>>>>>>>>>>> it
> > >>> > > > > >>>>>>>>>>>>>>>> to
> > >>> > > > > >>>>>>>>>>>>>>>>> IGNITE cache and creates *variable B *and
> > >>> > > > > >> sends
> > >>> > > > > >>>> it
> > >>> > > > > >>>>>> to*
> > >>> > > > > >>>>>>>>>> server2.
> > >>> > > > > >>>>>>>>>>>>> *The
> > >>> > > > > >>>>>>>>>>>>>>>>> latests receives *variable B*, do some
> logic
> > >>> > > > > >>> with
> > >>> > > > > >>>>> it
> > >>> > > > > >>>>>>> and
> > >>> > > > > >>>>>>>>>> stores
> > >>> > > > > >>>>>>>>>>>> to
> > >>> > > > > >>>>>>>>>>>>>>>> IGNITE.
> > >>> > > > > >>>>>>>>>>>>>>>>> All the work made by both servers must be
> > >>> > > > > >>>> fulfilled
> > >>> > > > > >>>>>> in
> > >>> > > > > >>>>>>>>> *one*
> > >>> > > > > >>>>>>>>>>>>>>> transaction.
> > >>> > > > > >>>>>>>>>>>>>>>>> Because we need all information done, or
> > >>> > > > > >>>>>>>>> nothing(rollbacked).
> > >>> > > > > >>>>>>>>>>> The
> > >>> > > > > >>>>>>>>>>>>>>>> scenario
> > >>> > > > > >>>>>>>>>>>>>>>>> is managed by orchestrator.
> > >>> > > > > >>>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>> вт, 14 мар. 2017 г. в 17:31, Sergi
> Vladykin <
> > >>> > > > > >>>>>>>>>>>>>> sergi.vladykin@gmail.com
> > >>> > > > > >>>>>>>>>>>>>>>> :
> > >>> > > > > >>>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>>> Ok, it is not a business case, it is your
> > >>> > > > > >>> wrong
> > >>> > > > > >>>>>>>> solution
> > >>> > > > > >>>>>>>>>> for
> > >>> > > > > >>>>>>>>>>>> it.
> > >>> > > > > >>>>>>>>>>>>>>>>>> Lets try again, what is the business case?
> > >>> > > > > >>>>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>>> Sergi
> > >>> > > > > >>>>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>>> 2017-03-14 16:42 GMT+03:00 ALEKSEY
> > >>> > > > > >> KUZNETSOV
> > >>> > > > > >>> <
> > >>> > > > > >>>>>>>>>>>>>>> alkuznetsov.sb@gmail.com
> > >>> > > > > >>>>>>>>>>>>>>>>> :
> > >>> > > > > >>>>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>>>> The case is the following, One starts
> > >>> > > > > >>>>> transaction
> > >>> > > > > >>>>>>> in
> > >>> > > > > >>>>>>>>> one
> > >>> > > > > >>>>>>>>>>>> node,
> > >>> > > > > >>>>>>>>>>>>>> and
> > >>> > > > > >>>>>>>>>>>>>>>>> commit
> > >>> > > > > >>>>>>>>>>>>>>>>>>> this transaction in another jvm node(or
> > >>> > > > > >>>>> rollback
> > >>> > > > > >>>>>> it
> > >>> > > > > >>>>>>>>>>>> remotely).
> > >>> > > > > >>>>>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>>>> вт, 14 мар. 2017 г. в 16:30, Sergi
> > >>> > > > > >>> Vladykin <
> > >>> > > > > >>>>>>>>>>>>>>>> sergi.vladykin@gmail.com
> > >>> > > > > >>>>>>>>>>>>>>>>>> :
> > >>> > > > > >>>>>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>>>>> Because even if you make it work for
> > >>> > > > > >> some
> > >>> > > > > >>>>>>>> simplistic
> > >>> > > > > >>>>>>>>>>>>> scenario,
> > >>> > > > > >>>>>>>>>>>>>>> get
> > >>> > > > > >>>>>>>>>>>>>>>>>> ready
> > >>> > > > > >>>>>>>>>>>>>>>>>>> to
> > >>> > > > > >>>>>>>>>>>>>>>>>>>> write many fault tolerance tests and
> > >>> > > > > >> make
> > >>> > > > > >>>>> sure
> > >>> > > > > >>>>>>> that
> > >>> > > > > >>>>>>>>> you
> > >>> > > > > >>>>>>>>>>> TXs
> > >>> > > > > >>>>>>>>>>>>>> work
> > >>> > > > > >>>>>>>>>>>>>>>>>>> gracefully
> > >>> > > > > >>>>>>>>>>>>>>>>>>>> in all modes in case of crashes. Also
> > >>> > > > > >>> make
> > >>> > > > > >>>>> sure
> > >>> > > > > >>>>>>>> that
> > >>> > > > > >>>>>>>>> we
> > >>> > > > > >>>>>>>>>>> do
> > >>> > > > > >>>>>>>>>>>>> not
> > >>> > > > > >>>>>>>>>>>>>>> have
> > >>> > > > > >>>>>>>>>>>>>>>>> any
> > >>> > > > > >>>>>>>>>>>>>>>>>>>> performance drops after all your
> > >>> > > > > >> changes
> > >>> > > > > >>> in
> > >>> > > > > >>>>>>>> existing
> > >>> > > > > >>>>>>>>>>>>>> benchmarks.
> > >>> > > > > >>>>>>>>>>>>>>>> All
> > >>> > > > > >>>>>>>>>>>>>>>>> in
> > >>> > > > > >>>>>>>>>>>>>>>>>>> all
> > >>> > > > > >>>>>>>>>>>>>>>>>>>> I don't believe these conditions will
> > >>> > > > > >> be
> > >>> > > > > >>>> met
> > >>> > > > > >>>>>> and
> > >>> > > > > >>>>>>>> your
> > >>> > > > > >>>>>>>>>>>>>>> contribution
> > >>> > > > > >>>>>>>>>>>>>>>>> will
> > >>> > > > > >>>>>>>>>>>>>>>>>>> be
> > >>> > > > > >>>>>>>>>>>>>>>>>>>> accepted.
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>>>>> Better solution to what problem?
> > >>> > > > > >> Sending
> > >>> > > > > >>> TX
> > >>> > > > > >>>>> to
> > >>> > > > > >>>>>>>>> another
> > >>> > > > > >>>>>>>>>>>> node?
> > >>> > > > > >>>>>>>>>>>>>> The
> > >>> > > > > >>>>>>>>>>>>>>>>>> problem
> > >>> > > > > >>>>>>>>>>>>>>>>>>>> statement itself is already wrong. What
> > >>> > > > > >>>>>> business
> > >>> > > > > >>>>>>>> case
> > >>> > > > > >>>>>>>>>> you
> > >>> > > > > >>>>>>>>>>>> are
> > >>> > > > > >>>>>>>>>>>>>>>> trying
> > >>> > > > > >>>>>>>>>>>>>>>>> to
> > >>> > > > > >>>>>>>>>>>>>>>>>>>> solve? I'm sure everything you need can
> > >>> > > > > >>> be
> > >>> > > > > >>>>> done
> > >>> > > > > >>>>>>> in
> > >>> > > > > >>>>>>>> a
> > >>> > > > > >>>>>>>>>> much
> > >>> > > > > >>>>>>>>>>>>> more
> > >>> > > > > >>>>>>>>>>>>>>>> simple
> > >>> > > > > >>>>>>>>>>>>>>>>>> and
> > >>> > > > > >>>>>>>>>>>>>>>>>>>> efficient way at the application level.
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>>>>> Sergi
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>>>>> 2017-03-14 16:03 GMT+03:00 ALEKSEY
> > >>> > > > > >>>> KUZNETSOV
> > >>> > > > > >>>>> <
> > >>> > > > > >>>>>>>>>>>>>>>>> alkuznetsov.sb@gmail.com
> > >>> > > > > >>>>>>>>>>>>>>>>>>> :
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>> Why wrong ? You know the better
> > >>> > > > > >>> solution?
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>> вт, 14 мар. 2017 г. в 15:46, Sergi
> > >>> > > > > >>>>> Vladykin <
> > >>> > > > > >>>>>>>>>>>>>>>>>> sergi.vladykin@gmail.com
> > >>> > > > > >>>>>>>>>>>>>>>>>>>> :
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>> Just serializing TX object and
> > >>> > > > > >>>>>> deserializing
> > >>> > > > > >>>>>>> it
> > >>> > > > > >>>>>>>>> on
> > >>> > > > > >>>>>>>>>>>>> another
> > >>> > > > > >>>>>>>>>>>>>>> node
> > >>> > > > > >>>>>>>>>>>>>>>>> is
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>> meaningless, because other nodes
> > >>> > > > > >>>>>>> participating
> > >>> > > > > >>>>>>>> in
> > >>> > > > > >>>>>>>>>> the
> > >>> > > > > >>>>>>>>>>>> TX
> > >>> > > > > >>>>>>>>>>>>>> have
> > >>> > > > > >>>>>>>>>>>>>>>> to
> > >>> > > > > >>>>>>>>>>>>>>>>>> know
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>> about
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>> the new coordinator. This will
> > >>> > > > > >>> require
> > >>> > > > > >>>>>>> protocol
> > >>> > > > > >>>>>>>>>>>> changes,
> > >>> > > > > >>>>>>>>>>>>> we
> > >>> > > > > >>>>>>>>>>>>>>>>>>> definitely
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>> will
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>> have fault tolerance and
> > >>> > > > > >> performance
> > >>> > > > > >>>>>> issues.
> > >>> > > > > >>>>>>>> IMO
> > >>> > > > > >>>>>>>>>> the
> > >>> > > > > >>>>>>>>>>>>> whole
> > >>> > > > > >>>>>>>>>>>>>>> idea
> > >>> > > > > >>>>>>>>>>>>>>>>> is
> > >>> > > > > >>>>>>>>>>>>>>>>>>>> wrong
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>> and it makes no sense to waste time
> > >>> > > > > >>> on
> > >>> > > > > >>>>> it.
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>> Sergi
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>> 2017-03-14 10:57 GMT+03:00 ALEKSEY
> > >>> > > > > >>>>>> KUZNETSOV
> > >>> > > > > >>>>>>> <
> > >>> > > > > >>>>>>>>>>>>>>>>>>> alkuznetsov.sb@gmail.com
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>> :
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>>> IgniteTransactionState
> > >>> > > > > >>>> implememntation
> > >>> > > > > >>>>>>>> contains
> > >>> > > > > >>>>>>>>>>>>>>>> IgniteTxEntry's
> > >>> > > > > >>>>>>>>>>>>>>>>>>> which
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>> is
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>>> supposed to be transferable
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>>> пн, 13 мар. 2017 г. в 19:32,
> > >>> > > > > >>> Dmitriy
> > >>> > > > > >>>>>>>> Setrakyan
> > >>> > > > > >>>>>>>>> <
> > >>> > > > > >>>>>>>>>>>>>>>>>>>> dsetrakyan@apache.org
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>> :
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>>>
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>>>>> It sounds a little scary to me
> > >>> > > > > >>> that
> > >>> > > > > >>>>> we
> > >>> > > > > >>>>>>> are
> > >>> > > > > >>>>>>>>>>> passing
> > >>> > > > > >>>>>>>>>>>>>>>>> transaction
> > >>> > > > > >>>>>>>>>>>>>>>>>>>>> objects
> > >>>
> > >>> --
> >
> > *Best Regards,*
> >
> > *Kuznetsov Aleksey*
> >
>
-- 

*Best Regards,*

*Kuznetsov Aleksey*

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