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From Alex Plehanov <plehanov.a...@gmail.com>
Subject Re: Thin client: transactions support
Date Mon, 27 May 2019 10:27:28 GMT
Ivan,

Yes, .NET client has such capability. Pavel Tupitsyn already mentions it in
this thread. As far as I understand, in .NET client implementation to
dispatch responses dedicated thread is used.
In a draft implementation of IGNITE-11685 I've used another approach: each
request thread can read a response (if lock is acquired by this thread
successfully) and complete a future of its own request or another threads
request.

пн, 27 мая 2019 г. в 13:01, Павлухин Иван <vololo100@gmail.com>:

> Alex,
>
> I am quite curious about async implementations from other clients. Is
> there any design document describing such implementations? Does .NET
> client have such capability?
>
> Actually, I forgot to finish my previous message. One of my concerns
> is that a concurrent response dispatch does not sound as a trivial
> thing. So, I would like to understand if we already have a good
> approach for that. If not then I suppose it worth a discussion.
>
> пн, 27 мая 2019 г. в 12:51, Alex Plehanov <plehanov.alex@gmail.com>:
> >
> > Hi Ivan.
> >
> > Thin client transactions support is not only for java thin client. There
> > are other clients, some of them already work in async mode.
> > Ticket IGNITE-11685 already has draft implementation too, but now it's
> > based on some changes to java thin client which were made by "transaction
> > support" implementation. I think this ticket will be ready in a couple of
> > days after "transaction support" will be merged. And both patches will be
> > included in the same release.
> >
> > пн, 27 мая 2019 г. в 11:57, Павлухин Иван <vololo100@gmail.com>:
> >
> > > Hi Alex,
> > >
> > > Regarding a problem with possible deadlock when two concurrent
> > > transactions from the same client are trying to lock the same key and
> > > an issue [1]. It seems to me that without fixing the issue [1] a
> > > client transactions feature is not practical. Everyone who uses a
> > > client from multiple threads can face a deadlock which is impossible
> > > to deal with. Or am I missing something here?
> > >
> > > One workaround I can imagine is failing a transactions execution from
> > > concurrent threads for a first time.
> > >
> > > [1] https://issues.apache.org/jira/browse/IGNITE-11685
> > >
> > > вт, 21 мая 2019 г. в 19:05, Alex Plehanov <plehanov.alex@gmail.com>:
> > > >
> > > > Guys,
> > > >
> > > > I've updated the IEP [1]. Please have a look.
> > > >
> > > > [1]
> > > >
> > >
> https://cwiki.apache.org/confluence/display/IGNITE/IEP-34+Thin+client%3A+transactions+support
> > > >
> > > >
> > > > вт, 21 мая 2019 г., 14:19 Alex Plehanov <plehanov.alex@gmail.com>:
> > > >
> > > > > Ivan,
> > > > >
> > > > > Yes, I have plans to do that (at least for java thin client).
> Something
> > > > > like new class "ClientTransactionConfiguration" inside
> > > > > "ClientConfiguration".
> > > > >
> > > > > вт, 21 мая 2019 г. в 13:37, Павлухин Иван <vololo100@gmail.com>:
> > > > >
> > > > >> Alex,
> > > > >>
> > > > >> Are you going to introduce settings specifying default values for
> tx
> > > > >> concurrency and isolation in client configuration?
> > > > >>
> > > > >> пн, 20 мая 2019 г. в 19:34, Alex Plehanov <
> plehanov.alex@gmail.com>:
> > > > >> >
> > > > >> > Igor,
> > > > >> >
> > > > >> > Perhaps we don't really need to use server's default values for
> tx
> > > > >> > parameters. It's a minor fix and can be easily implemented if it
> > > will be
> > > > >> > required in the future.
> > > > >> > I will update IEP tomorrow regarding point 1 and point 3.
> > > > >> > Thanks for your feedback.
> > > > >> >
> > > > >> > пн, 20 мая 2019 г. в 15:24, Igor Sapego <isapego@apache.org>:
> > > > >> >
> > > > >> > > Ivan,
> > > > >> > >
> > > > >> > > This may be a good point for a DBMS, but Ignite is much more
> than
> > > > >> just a
> > > > >> > > DBMS and Ignite client code is not just an SQL query (which
> > > execution
> > > > >> > > inherently heavily depends on DBMS). With database user is
> > > expecting
> > > > >> that
> > > > >> > > server have a lot of control on query execution. But with
> Ignite,
> > > in
> > > > >> my
> > > > >> > > opinion,
> > > > >> > > user writes generic code including business logic in native
> > > language
> > > > >> and
> > > > >> > > may
> > > > >> > > expect more deterministic behaviour from a client.
> > > > >> > >
> > > > >> > > Also, thick clients do not use server-side defaults.
> > > > >> > >
> > > > >> > > Of course, this question is debatable and It's not like I 100%
> > > against
> > > > >> > > server-side
> > > > >> > > defaults here, I just suggest to discuss it in more detail.
> > > > >> > >
> > > > >> > > Best Regards,
> > > > >> > > Igor
> > > > >> > >
> > > > >> > >
> > > > >> > > On Mon, May 20, 2019 at 2:21 PM Павлухин Иван <
> > > vololo100@gmail.com>
> > > > >> wrote:
> > > > >> > >
> > > > >> > > > Igor, Alex,
> > > > >> > > >
> > > > >> > > > Regarding point 1. I must say that SQL vendors usually
> allow to
> > > > >> > > > configure default timeouts and a transaction isolation on a
> > > server
> > > > >> > > > side. E.g. in MySQL you can do a following:
> > > > >> > > > set local tx_isolation = <isolation> -- per SQL client
> session
> > > > >> > > > (usually physical network connection)
> > > > >> > > > set global tx_isolation = <isolation> -- global settings,
> all
> > > > >> clients
> > > > >> > > > (which does not override it) are affected
> > > > >> > > >
> > > > >> > > > So, if it is a standard practice why should do it
> differently?
> > > If it
> > > > >> > > > is not, we can continue discussion. Do we have some examples
> > > > >> following
> > > > >> > > > opposite way (client-wide default setting)?
> > > > >> > > >
> > > > >> > > > пн, 20 мая 2019 г. в 13:50, Igor Sapego <isapego@apache.org
> >:
> > > > >> > > > >
> > > > >> > > > > 1. In my opinion, having client-specific transaction
> > > parameters is
> > > > >> > > > expected
> > > > >> > > > > for
> > > > >> > > > > client when have different arguments depending on server
> seems
> > > > >> > > unexpected
> > > > >> > > > > and can lead to hard-to-debug bugs and issues when
> updating
> > > from
> > > > >> old to
> > > > >> > > > new
> > > > >> > > > > server versions. Also it goes against common practice with
> > > > >> arguments of
> > > > >> > > > thin
> > > > >> > > > > client and thus, may be even more unexpected.
> > > > >> > > > >
> > > > >> > > > > I believe that if we want to add ability to client to
> adopt
> > > some
> > > > >> > > server's
> > > > >> > > > > defaults
> > > > >> > > > > we should implement it as separate feature, and it should
> not
> > > be a
> > > > >> > > > default
> > > > >> > > > > behaviour for client, user should explicitly state that
> they
> > > want
> > > > >> this
> > > > >> > > > > behaviour,
> > > > >> > > > > so it won't be unexpected for them.
> > > > >> > > > >
> > > > >> > > > > 3. "Flags" field looks like a good solution to me.
> > > > >> > > > >
> > > > >> > > > > Best Regards,
> > > > >> > > > > Igor
> > > > >> > > > >
> > > > >> > > > >
> > > > >> > > > > On Mon, May 20, 2019 at 12:58 PM Alex Plehanov <
> > > > >> > > plehanov.alex@gmail.com>
> > > > >> > > > > wrote:
> > > > >> > > > >
> > > > >> > > > > > Hi, Igor
> > > > >> > > > > >
> > > > >> > > > > > 1. I think it's better to have the ability to configure
> > > > >> transaction
> > > > >> > > > > > parameters (for example configure default timeout for
> all
> > > > >> clients) on
> > > > >> > > > > > server-side, then don't have such ability and always use
> > > some
> > > > >> > > > predefined
> > > > >> > > > > > client-side values (which can be different for different
> > > client
> > > > >> > > > > > implementations). At least default timeout is more
> server
> > > > >> specific
> > > > >> > > then
> > > > >> > > > > > client specific parameter since it can affect
> server-side
> > > > >> processes
> > > > >> > > > (PME
> > > > >> > > > > > for example).
> > > > >> > > > > >
> > > > >> > > > > > 2. IgniteUuid has 24 bytes length. This tx id needs to
> be
> > > > >> included to
> > > > >> > > > each
> > > > >> > > > > > cache operation under a transaction. And it almost will
> not
> > > > >> simplify
> > > > >> > > > server
> > > > >> > > > > > code. Also, thin clients don't know how to deal with
> > > IgniteUuid
> > > > >> now,
> > > > >> > > > there
> > > > >> > > > > > is no such entity in the protocol, there are no
> described
> > > rules
> > > > >> on
> > > > >> > > how
> > > > >> > > > to
> > > > >> > > > > > convert it to a string. For monitoring/debugging
> purposes we
> > > > >> should
> > > > >> > > > have
> > > > >> > > > > > the same presentation of this entity on server and
> client
> > > > >> sides. I
> > > > >> > > > think if
> > > > >> > > > > > we need to know real tx id on the client side it's
> better to
> > > > >> > > > additionally
> > > > >> > > > > > include this value to OP_TX_START response (we also can
> > > > >> serialize it
> > > > >> > > > as a
> > > > >> > > > > > string to avoid introducing new entity on client side)
> or
> > > > >> create a
> > > > >> > > new
> > > > >> > > > > > operation to explicitly request tx id (for example
> > > OP_TX_INFO).
> > > > >> > > > > >
> > > > >> > > > > > 3. Make sense, we can reuse deprecated "flags" field
> > > > >> (undeprecate
> > > > >> > > it),
> > > > >> > > > > > which is included now to each cache operation.
> > > > >> > > > > >
> > > > >> > > > > >
> > > > >> > > > > > пт, 17 мая 2019 г. в 18:49, Igor Sapego <
> isapego@apache.org
> > > >:
> > > > >> > > > > >
> > > > >> > > > > > > Hi,
> > > > >> > > > > > >
> > > > >> > > > > > > I had a look at IEP and have several comments:
> > > > >> > > > > > >
> > > > >> > > > > > > 1. Why would one want to use to use server's default
> > > values
> > > > >> for
> > > > >> > > > > > Concurrency
> > > > >> > > > > > > or Isolation?
> > > > >> > > > > > > I believe, client should have its own defaults which
> > > should be
> > > > >> > > > explicitly
> > > > >> > > > > > > documented, so that
> > > > >> > > > > > > behaviour of transactions will not depend on the
> server
> > > node
> > > > >> it was
> > > > >> > > > > > routed
> > > > >> > > > > > > to. The same goes
> > > > >> > > > > > > for timeout.
> > > > >> > > > > > >
> > > > >> > > > > > > 2. Not sure about transaction ID represented by int.
> Why
> > > not
> > > > >> to use
> > > > >> > > > > > > IgniteUuid? It should simplify
> > > > >> > > > > > > server code. Also it may help with
> monitoring/debugging if
> > > > >> thin
> > > > >> > > > clients
> > > > >> > > > > > and
> > > > >> > > > > > > server nodes use the
> > > > >> > > > > > > same identifier for transactions. It does not seem as
> a
> > > big
> > > > >> > > overhead
> > > > >> > > > to
> > > > >> > > > > > me
> > > > >> > > > > > > either.
> > > > >> > > > > > >
> > > > >> > > > > > > 3. Maybe it makes sense to add "In transaction"
> boolean
> > > flag
> > > > >> to
> > > > >> > > cache
> > > > >> > > > > > > operation request header
> > > > >> > > > > > > to avoid bloating message size in non-affected
> scenarios.
> > > > >> > > > > > >
> > > > >> > > > > > > Best Regards,
> > > > >> > > > > > > Igor
> > > > >> > > > > > >
> > > > >> > > > > > >
> > > > >> > > > > > > On Mon, May 13, 2019 at 1:58 PM Alex Plehanov <
> > > > >> > > > plehanov.alex@gmail.com>
> > > > >> > > > > > > wrote:
> > > > >> > > > > > >
> > > > >> > > > > > > > Hi, Ivan.
> > > > >> > > > > > > >
> > > > >> > > > > > > > Thanks for your comments.
> > > > >> > > > > > > >
> > > > >> > > > > > > > 1. Transaction id in thin client protocol it's just
> a tx
> > > > >> counter
> > > > >> > > > for
> > > > >> > > > > > the
> > > > >> > > > > > > > current connection. It's not related to
> > > GridCacheVersion.
> > > > >> If we
> > > > >> > > > want to
> > > > >> > > > > > > > know GridCacheVersion on the client side, I think we
> > > should
> > > > >> > > > introduce a
> > > > >> > > > > > > new
> > > > >> > > > > > > > type of operation (for example OP_TX_INFO).
> > > > >> > > > > > > > 2. Error handling is already provided by thin client
> > > > >> protocol,
> > > > >> > > > even in
> > > > >> > > > > > > case
> > > > >> > > > > > > > of empty response. Of course, the client will know
> if
> > > there
> > > > >> is a
> > > > >> > > > > > failure
> > > > >> > > > > > > > occurred during OP_TX_END operation.
> > > > >> > > > > > > > 3. AFAIK some of thin client implementations already
> > > send
> > > > >> > > requests
> > > > >> > > > and
> > > > >> > > > > > > > process responses in an async way (.NET for
> example). As
> > > > >> for java
> > > > >> > > > thin
> > > > >> > > > > > > > client, in the current implementation channel is
> locked
> > > > >> > > exclusively
> > > > >> > > > > > > before
> > > > >> > > > > > > > request send and until the response is processed. I
> have
> > > > >> some
> > > > >> > > ideas
> > > > >> > > > > > about
> > > > >> > > > > > > > how to fix this (split send/receive process into two
> > > > >> different
> > > > >> > > > parts
> > > > >> > > > > > and
> > > > >> > > > > > > > acquire locks for this parts separately or create
> > > futures on
> > > > >> > > > request
> > > > >> > > > > > sent
> > > > >> > > > > > > > and complete it after processing the response in a
> > > dedicated
> > > > >> > > > thread),
> > > > >> > > > > > > I've
> > > > >> > > > > > > > created ticket [1] for this issue and will try to
> > > implement
> > > > >> > > > prototype
> > > > >> > > > > > in
> > > > >> > > > > > > a
> > > > >> > > > > > > > couple of days.
> > > > >> > > > > > > >
> > > > >> > > > > > > > About suspend/resume, yes, on server-side we should
> > > resume
> > > > >> tx
> > > > >> > > > before
> > > > >> > > > > > each
> > > > >> > > > > > > > transactional cache operation and suspend the tx
> after
> > > the
> > > > >> > > > operation.
> > > > >> > > > > > In
> > > > >> > > > > > > my
> > > > >> > > > > > > > opinion, suspend/resume approach have several
> advantages
> > > > >> over
> > > > >> > > > approach
> > > > >> > > > > > > with
> > > > >> > > > > > > > explicit tx id argument:
> > > > >> > > > > > > > - Introducing explicit tx id argument for cache
> > > operations
> > > > >> leads
> > > > >> > > > to a
> > > > >> > > > > > > > significant API change
> > > > >> > > > > > > > - It's not clear how to use it together with current
> > > > >> > > > (tx-per-thread)
> > > > >> > > > > > > > approach (for example, what if a thread is already
> held
> > > > >> > > > transaction and
> > > > >> > > > > > > > someone call cache operation with explicit tx id?)
> > > > >> > > > > > > > - Suspend/resume feature will also be useful for
> thick
> > > > >> clients
> > > > >> > > > > > > > - Suspend/resume functionality is already partially
> > > > >> implemented
> > > > >> > > > (for
> > > > >> > > > > > > > optimistic transactions only)
> > > > >> > > > > > > >
> > > > >> > > > > > > > [1]
> https://issues.apache.org/jira/browse/IGNITE-11685
> > > > >> > > > > > > >
> > > > >> > > > > > > > пт, 3 мая 2019 г. в 08:10, Павлухин Иван <
> > > > >> vololo100@gmail.com>:
> > > > >> > > > > > > >
> > > > >> > > > > > > > > Hi Alex,
> > > > >> > > > > > > > >
> > > > >> > > > > > > > > I went through IEP [1] and I have a couple of
> > > questions:
> > > > >> > > > > > > > > 1. What is going to be used as transaction id? In
> a
> > > > >> described
> > > > >> > > > > > protocol
> > > > >> > > > > > > > > I see an int field for it. Should not it be
> > > > >> GridCacheVersion
> > > > >> > > > > > > > > corresponding to IgniteInternalTx#xidVersion?
> > > > >> > > > > > > > > 2. OP_TX_END message assumes an empty response,
> but I
> > > > >> think
> > > > >> > > that
> > > > >> > > > > > > > > errors during tx finish are possible and should be
> > > > >> returned in
> > > > >> > > a
> > > > >> > > > > > > > > response.
> > > > >> > > > > > > > > 3. In IEP it is stated that async processing of
> lock
> > > > >> operations
> > > > >> > > > > > should
> > > > >> > > > > > > > > be introduced on a client side to enable
> concurrent
> > > > >> operations
> > > > >> > > > from
> > > > >> > > > > > > > > different client threads. Do you have an idea how
> to
> > > > >> achieve
> > > > >> > > it?
> > > > >> > > > > > > > >
> > > > >> > > > > > > > > Also, a bit about a suspend/resume trait. I tried
> to
> > > think
> > > > >> > > about
> > > > >> > > > it
> > > > >> > > > > > > > > leaving away an existing transactions
> implementation
> > > in
> > > > >> Ignite.
> > > > >> > > > As I
> > > > >> > > > > > > > > understood we are going to resume a tx before each
> > > cache
> > > > >> > > > operation in
> > > > >> > > > > > > > > the tx and resume the tx after the operation. All
> > > this to
> > > > >> make
> > > > >> > > an
> > > > >> > > > > > > > > executing thread available for other operations
> (e.g.
> > > in
> > > > >> other
> > > > >> > > > txs).
> > > > >> > > > > > > > > From the first glance it seems like an inversed
> > > logic. A
> > > > >> > > > > > > > > straightforward way is to execute a cache
> operation
> > > > >> within a
> > > > >> > > > > > > > > particular transaction defined as an explicit tx
> id
> > > > >> argument
> > > > >> > > > (e.g.
> > > > >> > > > > > > > > cache.put(key, value, txid)). Can we do so?
> > > > >> > > > > > > > >
> > > > >> > > > > > > > > And leaving for now thin client API. I cannot say
> > > that one
> > > > >> > > > proposed
> > > > >> > > > > > in
> > > > >> > > > > > > > > IEP is good or bad. I can only say that it
> ressembles
> > > > >> current
> > > > >> > > > thick
> > > > >> > > > > > > > > client API. And perhaps it should not. I think
> that we
> > > > >> should
> > > > >> > > > > > consider
> > > > >> > > > > > > > > similar APIs provided by other vendors and keep in
> > > mind
> > > > >> that we
> > > > >> > > > have
> > > > >> > > > > > a
> > > > >> > > > > > > > > bunch of client implementations for different
> > > languages. I
> > > > >> > > > suppose
> > > > >> > > > > > > > > that we can return to it a little bit later. And I
> > > hope
> > > > >> that we
> > > > >> > > > will
> > > > >> > > > > > > > > do it.
> > > > >> > > > > > > > >
> > > > >> > > > > > > > > [1]
> > > > >> > > > > > > > >
> > > > >> > > > > > > >
> > > > >> > > > > > >
> > > > >> > > > > >
> > > > >> > > >
> > > > >> > >
> > > > >>
> > >
> https://cwiki.apache.org/confluence/display/IGNITE/IEP-34+Thin+client%3A+transactions+support
> > > > >> > > > > > > > >
> > > > >> > > > > > > > > вт, 30 апр. 2019 г. в 13:24, Alex Plehanov <
> > > > >> > > > plehanov.alex@gmail.com
> > > > >> > > > > > >:
> > > > >> > > > > > > > > >
> > > > >> > > > > > > > > > Hello, Igniters!
> > > > >> > > > > > > > > >
> > > > >> > > > > > > > > > I've update IEP [1] and implement PoC according
> to
> > > new
> > > > >> > > approach
> > > > >> > > > > > > > (multiple
> > > > >> > > > > > > > > > concurrent transactions per connection).
> > > > >> > > > > > > > > > But to move forward another feature need to be
> > > > >> implemented:
> > > > >> > > > > > > > > suspend/resume
> > > > >> > > > > > > > > > for pessimistic transactions (IGNITE-5714 [2]).
> > > > >> > > Implementation
> > > > >> > > > of
> > > > >> > > > > > > > > > suspend/resume is ready now and ticket in 'Patch
> > > > >> available'
> > > > >> > > > status.
> > > > >> > > > > > > Can
> > > > >> > > > > > > > > any
> > > > >> > > > > > > > > > transactions expert help with review of
> IGNITE-5714?
> > > > >> > > > > > > > > >
> > > > >> > > > > > > > > > [1]:
> > > > >> > > > > > > > > >
> > > > >> > > > > > > > >
> > > > >> > > > > > > >
> > > > >> > > > > > >
> > > > >> > > > > >
> > > > >> > > >
> > > > >> > >
> > > > >>
> > >
> https://cwiki.apache.org/confluence/display/IGNITE/IEP-34+Thin+client%3A+transactions+support
> > > > >> > > > > > > > > > [2]:
> > > https://issues.apache.org/jira/browse/IGNITE-5714
> > > > >> > > > > > > > > >
> > > > >> > > > > > > > > > чт, 4 апр. 2019 г. в 11:32, Alex Plehanov <
> > > > >> > > > plehanov.alex@gmail.com
> > > > >> > > > > > >:
> > > > >> > > > > > > > > >
> > > > >> > > > > > > > > > > Vladimir,
> > > > >> > > > > > > > > > >
> > > > >> > > > > > > > > > > Ok, then I will rewrite IEP in the near
> future.
> > > > >> > > > > > > > > > >
> > > > >> > > > > > > > > > > чт, 4 апр. 2019 г. в 11:14, Vladimir Ozerov <
> > > > >> > > > > > vozerov@gridgain.com
> > > > >> > > > > > > >:
> > > > >> > > > > > > > > > >
> > > > >> > > > > > > > > > >> Hi Alex,
> > > > >> > > > > > > > > > >>
> > > > >> > > > > > > > > > >> I think we should be able to handle many
> > > transactions
> > > > >> > > > through a
> > > > >> > > > > > > > single
> > > > >> > > > > > > > > > >> connection. This will make our protocol and
> > > client
> > > > >> > > > > > implementations
> > > > >> > > > > > > > > much
> > > > >> > > > > > > > > > >> more efficient, and simplicity from
> developer's
> > > > >> > > perspective
> > > > >> > > > is
> > > > >> > > > > > not
> > > > >> > > > > > > > our
> > > > >> > > > > > > > > > >> goal. Consider normal nodes. We have server
> > > nodes and
> > > > >> > > client
> > > > >> > > > > > > nodes.
> > > > >> > > > > > > > > You
> > > > >> > > > > > > > > > >> may
> > > > >> > > > > > > > > > >> span whatever number of transactions you
> need,
> > > but
> > > > >> all of
> > > > >> > > > them
> > > > >> > > > > > are
> > > > >> > > > > > > > > > >> coordinated through a single connection. The
> same
> > > > >> should
> > > > >> > > be
> > > > >> > > > > > > > > applicable to
> > > > >> > > > > > > > > > >> thin clients. Protocol is already designed to
> > > handle
> > > > >> this,
> > > > >> > > > as we
> > > > >> > > > > > > > pass
> > > > >> > > > > > > > > > >> unique operation ID in order to distinguish
> one
> > > > >> operation
> > > > >> > > > from
> > > > >> > > > > > > > > another. It
> > > > >> > > > > > > > > > >> is true, though, that we will have to
> introduce a
> > > > >> kind of
> > > > >> > > > > > > "session"
> > > > >> > > > > > > > > > >> concept, and pass additional identifier along
> > > with
> > > > >> cache
> > > > >> > > > > > > operations,
> > > > >> > > > > > > > > but
> > > > >> > > > > > > > > > >> this doesn't sound like a problem to me.
> > > > >> > > > > > > > > > >>
> > > > >> > > > > > > > > > >> And provided that currently server-side
> > > transactions
> > > > >> are
> > > > >> > > > bound
> > > > >> > > > > > to
> > > > >> > > > > > > > > threads
> > > > >> > > > > > > > > > >> artificially, I would say that the first
> step in
> > > > >> > > > implementation
> > > > >> > > > > > of
> > > > >> > > > > > > > > > >> transactions on thin clients should be
> decoupling
> > > > >> > > > server-side
> > > > >> > > > > > > > > transactions
> > > > >> > > > > > > > > > >> from threads. Without this we will have very
> > > > >> inefficient
> > > > >> > > > > > > > > implementation,
> > > > >> > > > > > > > > > >> when every new client transaction have to
> spawn
> > > a new
> > > > >> > > > thread.
> > > > >> > > > > > This
> > > > >> > > > > > > > is
> > > > >> > > > > > > > > slow
> > > > >> > > > > > > > > > >> and introduces high memory pressure on a
> cluster
> > > > >> node. We
> > > > >> > > > > > already
> > > > >> > > > > > > > work
> > > > >> > > > > > > > > > >> this
> > > > >> > > > > > > > > > >> way for MVCC transactions which are spawned
> from
> > > JDBC
> > > > >> > > > driver,
> > > > >> > > > > > and
> > > > >> > > > > > > > > believe
> > > > >> > > > > > > > > > >> me, we do not want to replicated this bad
> > > practice to
> > > > >> > > other
> > > > >> > > > > > > clients
> > > > >> > > > > > > > > :-)
> > > > >> > > > > > > > > > >>
> > > > >> > > > > > > > > > >> Vladimir.
> > > > >> > > > > > > > > > >>
> > > > >> > > > > > > > > > >> On Thu, Apr 4, 2019 at 10:08 AM Alex
> Plehanov <
> > > > >> > > > > > > > > plehanov.alex@gmail.com>
> > > > >> > > > > > > > > > >> wrote:
> > > > >> > > > > > > > > > >>
> > > > >> > > > > > > > > > >> > Guys, so, do we need multiple concurrent
> > > > >> transactions
> > > > >> > > per
> > > > >> > > > > > > > > connection?
> > > > >> > > > > > > > > > >> >
> > > > >> > > > > > > > > > >> > There are pros and cons for each approach.
> > > > >> Difference
> > > > >> > > > between
> > > > >> > > > > > > > > > >> approaches:
> > > > >> > > > > > > > > > >> >
> > > > >> > > > > > > > > > >> > One transaction at a time per connection:
> > > > >> > > > > > > > > > >> >  - This approach is used in RDBMS world and
> > > users
> > > > >> got
> > > > >> > > > used to
> > > > >> > > > > > it
> > > > >> > > > > > > > > > >> >  - To use transactions concurrently users
> need
> > > to
> > > > >> use
> > > > >> > > > > > different
> > > > >> > > > > > > > > > >> connections
> > > > >> > > > > > > > > > >> > and get these connections via something
> like a
> > > > >> > > connection
> > > > >> > > > pool
> > > > >> > > > > > > > > > >> >  - Easy to implement (in fact, PoC is
> already
> > > done)
> > > > >> > > > > > > > > > >> >
> > > > >> > > > > > > > > > >> > Multiple concurrent transactions per
> > > connection:
> > > > >> > > > > > > > > > >> >  - At least for java thin client, we can
> > > implement
> > > > >> > > > transaction
> > > > >> > > > > > > per
> > > > >> > > > > > > > > > >> thread
> > > > >> > > > > > > > > > >> > approach as implemented now for the thick
> > > client
> > > > >> > > (perhaps
> > > > >> > > > > > other
> > > > >> > > > > > > > thin
> > > > >> > > > > > > > > > >> > clients can implement the same abstraction)
> > > > >> > > > > > > > > > >> >  - There is also protocol change for all
> cache
> > > > >> > > operations
> > > > >> > > > > > needed
> > > > >> > > > > > > > (to
> > > > >> > > > > > > > > > >> bind
> > > > >> > > > > > > > > > >> > cache operation to the transaction)
> > > > >> > > > > > > > > > >> >  - Significant changes to all implemented
> > > clients
> > > > >> are
> > > > >> > > > needed
> > > > >> > > > > > > > > > >> >  - Implementation on the server side is
> more
> > > > >> complex
> > > > >> > > > > > > > > > >> >
> > > > >> > > > > > > > > > >> > What do you think?
> > > > >> > > > > > > > > > >> >
> > > > >> > > > > > > > > > >> >
> > > > >> > > > > > > > > > >> > вт, 2 апр. 2019 г. в 16:29, Alex Plehanov <
> > > > >> > > > > > > > plehanov.alex@gmail.com
> > > > >> > > > > > > > > >:
> > > > >> > > > > > > > > > >> >
> > > > >> > > > > > > > > > >> > > Ilya,
> > > > >> > > > > > > > > > >> > >
> > > > >> > > > > > > > > > >> > > > We should be able to multiplex several
> > > > >> transactions
> > > > >> > > > using
> > > > >> > > > > > a
> > > > >> > > > > > > > > single
> > > > >> > > > > > > > > > >> > > Client connection.
> > > > >> > > > > > > > > > >> > > In this case, we should significantly
> change
> > > > >> cache
> > > > >> > > > > > operations
> > > > >> > > > > > > > > syntax
> > > > >> > > > > > > > > > >> (for
> > > > >> > > > > > > > > > >> > > each implemented client), to bind each
> > > operation
> > > > >> to
> > > > >> > > the
> > > > >> > > > > > > > > transaction.
> > > > >> > > > > > > > > > >> > >
> > > > >> > > > > > > > > > >> > > > I want to also ask if "Number of
> entries
> > > > >> > > > participating in
> > > > >> > > > > > > > > > >> transaction
> > > > >> > > > > > > > > > >> > > (may be approximate). 0 - default
> value." is
> > > > >> needed.
> > > > >> > > > > > > > > > >> > > I've tried to minimize API changes
> between
> > > thick
> > > > >> and
> > > > >> > > > thin
> > > > >> > > > > > > client
> > > > >> > > > > > > > > to
> > > > >> > > > > > > > > > >> > > simplify move from one to another. It's
> the
> > > only
> > > > >> > > reason.
> > > > >> > > > > > But I
> > > > >> > > > > > > > > agree
> > > > >> > > > > > > > > > >> with
> > > > >> > > > > > > > > > >> > > you, the parameter is not very useful.
> > > > >> > > > > > > > > > >> > >
> > > > >> > > > > > > > > > >> > >
> > > > >> > > > > > > > > > >> > > вт, 2 апр. 2019 г. в 14:48, Ilya
> Kasnacheev <
> > > > >> > > > > > > > > > >> ilya.kasnacheev@gmail.com>:
> > > > >> > > > > > > > > > >> > >
> > > > >> > > > > > > > > > >> > >> Hello!
> > > > >> > > > > > > > > > >> > >>
> > > > >> > > > > > > > > > >> > >> Pavel, I agree with you thorougly. We
> > > should be
> > > > >> able
> > > > >> > > to
> > > > >> > > > > > > > multiplex
> > > > >> > > > > > > > > > >> > several
> > > > >> > > > > > > > > > >> > >> transactions using a single Client
> > > connection.
> > > > >> This
> > > > >> > > > means
> > > > >> > > > > > > > adding
> > > > >> > > > > > > > > > >> > >> Transaction id parameter to every
> affected
> > > cache
> > > > >> > > > operation
> > > > >> > > > > > /
> > > > >> > > > > > > > SQL
> > > > >> > > > > > > > > > >> > statement
> > > > >> > > > > > > > > > >> > >> (if applicable) to make sure we do cache
> > > > >> operations
> > > > >> > > on
> > > > >> > > > > > > relevant
> > > > >> > > > > > > > > > >> > >> transaction.
> > > > >> > > > > > > > > > >> > >>
> > > > >> > > > > > > > > > >> > >> This is how other things work in Ignite,
> > > such as
> > > > >> > > > > > > communication.
> > > > >> > > > > > > > > We do
> > > > >> > > > > > > > > > >> > not
> > > > >> > > > > > > > > > >> > >> open dozens of connections, we multiplex
> > > > >> operations
> > > > >> > > > > > > > > asynchronously
> > > > >> > > > > > > > > > >> > through
> > > > >> > > > > > > > > > >> > >> a single connection.
> > > > >> > > > > > > > > > >> > >>
> > > > >> > > > > > > > > > >> > >> I think that trying to pool Ignite
> > > connections
> > > > >> will
> > > > >> > > be
> > > > >> > > > > > highly
> > > > >> > > > > > > > > > >> > >> inconvenient,
> > > > >> > > > > > > > > > >> > >> since there is no existing
> infrastructure
> > > for
> > > > >> such
> > > > >> > > > pooling
> > > > >> > > > > > > > (like
> > > > >> > > > > > > > > > >> there
> > > > >> > > > > > > > > > >> > >> exists for JDBC).
> > > > >> > > > > > > > > > >> > >>
> > > > >> > > > > > > > > > >> > >> I want to also ask if "Number of entries
> > > > >> > > participating
> > > > >> > > > in
> > > > >> > > > > > > > > transaction
> > > > >> > > > > > > > > > >> > (may
> > > > >> > > > > > > > > > >> > >> be approximate). 0 - default value." is
> > > needed.
> > > > >> Does
> > > > >> > > it
> > > > >> > > > > > > > actually
> > > > >> > > > > > > > > do
> > > > >> > > > > > > > > > >> > >> anything in our tx protocol? Users of
> > > existing
> > > > >> APIs
> > > > >> > > are
> > > > >> > > > > > > already
> > > > >> > > > > > > > > > >> confused
> > > > >> > > > > > > > > > >> > >> by
> > > > >> > > > > > > > > > >> > >> this parameter, if we could get rid of
> it in
> > > > >> thin
> > > > >> > > > client
> > > > >> > > > > > > > > protocol it
> > > > >> > > > > > > > > > >> > would
> > > > >> > > > > > > > > > >> > >> be nice clean-up.
> > > > >> > > > > > > > > > >> > >>
> > > > >> > > > > > > > > > >> > >> Regards,
> > > > >> > > > > > > > > > >> > >> --
> > > > >> > > > > > > > > > >> > >> Ilya Kasnacheev
> > > > >> > > > > > > > > > >> > >>
> > > > >> > > > > > > > > > >> > >>
> > > > >> > > > > > > > > > >> > >> вт, 2 апр. 2019 г. в 09:55, Pavel
> Tupitsyn <
> > > > >> > > > > > > > ptupitsyn@apache.org
> > > > >> > > > > > > > > >:
> > > > >> > > > > > > > > > >> > >>
> > > > >> > > > > > > > > > >> > >> > Alex,
> > > > >> > > > > > > > > > >> > >> >
> > > > >> > > > > > > > > > >> > >> > > now we can only support one active
> > > > >> transaction
> > > > >> > > per
> > > > >> > > > > > > > connection
> > > > >> > > > > > > > > > >> > >> >
> > > > >> > > > > > > > > > >> > >> > I totally understand server-side and
> > > protocol
> > > > >> > > > limitations
> > > > >> > > > > > > > that
> > > > >> > > > > > > > > are
> > > > >> > > > > > > > > > >> > >> causing
> > > > >> > > > > > > > > > >> > >> > this.
> > > > >> > > > > > > > > > >> > >> > But I have no idea how to support
> this in
> > > > >> .NET Thin
> > > > >> > > > > > Client,
> > > > >> > > > > > > > for
> > > > >> > > > > > > > > > >> > example.
> > > > >> > > > > > > > > > >> > >> >
> > > > >> > > > > > > > > > >> > >> > It is thread-safe and can handle
> multiple
> > > > >> async
> > > > >> > > > > > operations
> > > > >> > > > > > > in
> > > > >> > > > > > > > > > >> > parallel.
> > > > >> > > > > > > > > > >> > >> > But with TX support we have to somehow
> > > switch
> > > > >> to
> > > > >> > > > > > > > > single-threaded
> > > > >> > > > > > > > > > >> mode
> > > > >> > > > > > > > > > >> > to
> > > > >> > > > > > > > > > >> > >> > avoid unexpected effects.
> > > > >> > > > > > > > > > >> > >> >
> > > > >> > > > > > > > > > >> > >> > Any ideas?
> > > > >> > > > > > > > > > >> > >> >
> > > > >> > > > > > > > > > >> > >> >
> > > > >> > > > > > > > > > >> > >> > On Mon, Apr 1, 2019 at 6:38 PM Alex
> > > Plehanov <
> > > > >> > > > > > > > > > >> plehanov.alex@gmail.com
> > > > >> > > > > > > > > > >> > >
> > > > >> > > > > > > > > > >> > >> > wrote:
> > > > >> > > > > > > > > > >> > >> >
> > > > >> > > > > > > > > > >> > >> > > Dmitriy, thank you!
> > > > >> > > > > > > > > > >> > >> > >
> > > > >> > > > > > > > > > >> > >> > > Guys, I've created the IEP [1] on
> wiki,
> > > > >> please
> > > > >> > > > have a
> > > > >> > > > > > > look.
> > > > >> > > > > > > > > > >> > >> > >
> > > > >> > > > > > > > > > >> > >> > > [1]
> > > > >> > > > > > > > > > >> > >> > >
> > > > >> > > > > > > > > > >> > >> > >
> > > > >> > > > > > > > > > >> > >> >
> > > > >> > > > > > > > > > >> > >>
> > > > >> > > > > > > > > > >> >
> > > > >> > > > > > > > > > >>
> > > > >> > > > > > > > >
> > > > >> > > > > > > >
> > > > >> > > > > > >
> > > > >> > > > > >
> > > > >> > > >
> > > > >> > >
> > > > >>
> > >
> https://cwiki.apache.org/confluence/display/IGNITE/IEP-34+Thin+client%3A+transactions+support
> > > > >> > > > > > > > > > >> > >> > >
> > > > >> > > > > > > > > > >> > >> > >
> > > > >> > > > > > > > > > >> > >> > > чт, 28 мар. 2019 г. в 14:33, Dmitriy
> > > Pavlov
> > > > >> <
> > > > >> > > > > > > > > dpavlov@apache.org
> > > > >> > > > > > > > > > >> >:
> > > > >> > > > > > > > > > >> > >> > >
> > > > >> > > > > > > > > > >> > >> > > > Hi,
> > > > >> > > > > > > > > > >> > >> > > >
> > > > >> > > > > > > > > > >> > >> > > > I've added permissions to account
> > > > >> plehanov.alex
> > > > >> > > > > > > > > > >> > >> > > >
> > > > >> > > > > > > > > > >> > >> > > > Recently Infra integrated Apache
> LDAP
> > > with
> > > > >> > > > > > confluence,
> > > > >> > > > > > > so
> > > > >> > > > > > > > > it is
> > > > >> > > > > > > > > > >> > >> > possible
> > > > >> > > > > > > > > > >> > >> > > to
> > > > >> > > > > > > > > > >> > >> > > > login using Apache credentials.
> > > Probably
> > > > >> we can
> > > > >> > > > ask
> > > > >> > > > > > > infra
> > > > >> > > > > > > > > if
> > > > >> > > > > > > > > > >> extra
> > > > >> > > > > > > > > > >> > >> > > > permissions to edit pages should
> be
> > > added
> > > > >> for
> > > > >> > > > > > > committers.
> > > > >> > > > > > > > > > >> > >> > > >
> > > > >> > > > > > > > > > >> > >> > > > Sincerely,
> > > > >> > > > > > > > > > >> > >> > > > Dmitriy Pavlov
> > > > >> > > > > > > > > > >> > >> > > >
> > > > >> > > > > > > > > > >> > >> > > > ср, 27 мар. 2019 г. в 13:37, Alex
> > > > >> Plehanov <
> > > > >> > > > > > > > > > >> > plehanov.alex@gmail.com
> > > > >> > > > > > > > > > >> > >> >:
> > > > >> > > > > > > > > > >> > >> > > >
> > > > >> > > > > > > > > > >> > >> > > > > Vladimir,
> > > > >> > > > > > > > > > >> > >> > > > >
> > > > >> > > > > > > > > > >> > >> > > > > About current tx: ok, then we
> don't
> > > > >> need tx()
> > > > >> > > > > > method
> > > > >> > > > > > > in
> > > > >> > > > > > > > > the
> > > > >> > > > > > > > > > >> > >> interface
> > > > >> > > > > > > > > > >> > >> > > at
> > > > >> > > > > > > > > > >> > >> > > > > all (the same cached transaction
> > > info
> > > > >> user
> > > > >> > > can
> > > > >> > > > > > store
> > > > >> > > > > > > by
> > > > >> > > > > > > > > > >> > himself).
> > > > >> > > > > > > > > > >> > >> > > > >
> > > > >> > > > > > > > > > >> > >> > > > > About decoupling transactions
> from
> > > > >> threads on
> > > > >> > > > the
> > > > >> > > > > > > > server
> > > > >> > > > > > > > > > >> side:
> > > > >> > > > > > > > > > >> > for
> > > > >> > > > > > > > > > >> > >> > now,
> > > > >> > > > > > > > > > >> > >> > > > we
> > > > >> > > > > > > > > > >> > >> > > > > can start with
> thread-per-connection
> > > > >> approach
> > > > >> > > > (we
> > > > >> > > > > > > only
> > > > >> > > > > > > > > can
> > > > >> > > > > > > > > > >> > support
> > > > >> > > > > > > > > > >> > >> > one
> > > > >> > > > > > > > > > >> > >> > > > > active transaction per
> connection,
> > > see
> > > > >> below,
> > > > >> > > > so we
> > > > >> > > > > > > > need
> > > > >> > > > > > > > > one
> > > > >> > > > > > > > > > >> > >> > additional
> > > > >> > > > > > > > > > >> > >> > > > > dedicated thread for each
> connection
> > > > >> with
> > > > >> > > > active
> > > > >> > > > > > > > > > >> transaction),
> > > > >> > > > > > > > > > >> > and
> > > > >> > > > > > > > > > >> > >> > > later
> > > > >> > > > > > > > > > >> > >> > > > > change server-side internals to
> > > process
> > > > >> > > client
> > > > >> > > > > > > > > transactions
> > > > >> > > > > > > > > > >> in
> > > > >> > > > > > > > > > >> > any
> > > > >> > > > > > > > > > >> > >> > > server
> > > > >> > > > > > > > > > >> > >> > > > > thread (not dedicated to this
> > > > >> connection).
> > > > >> > > This
> > > > >> > > > > > > change
> > > > >> > > > > > > > > will
> > > > >> > > > > > > > > > >> not
> > > > >> > > > > > > > > > >> > >> > affect
> > > > >> > > > > > > > > > >> > >> > > > the
> > > > >> > > > > > > > > > >> > >> > > > > thin client protocol, it only
> > > affects
> > > > >> the
> > > > >> > > > server
> > > > >> > > > > > > side.
> > > > >> > > > > > > > > > >> > >> > > > > In any case, we can't support
> > > concurrent
> > > > >> > > > > > transactions
> > > > >> > > > > > > > per
> > > > >> > > > > > > > > > >> > >> connection
> > > > >> > > > > > > > > > >> > >> > on
> > > > >> > > > > > > > > > >> > >> > > > > the client side without
> fundamental
> > > > >> changes
> > > > >> > > to
> > > > >> > > > the
> > > > >> > > > > > > > > current
> > > > >> > > > > > > > > > >> > >> protocol
> > > > >> > > > > > > > > > >> > >> > > > (cache
> > > > >> > > > > > > > > > >> > >> > > > > operation doesn't bound to
> > > transaction
> > > > >> or
> > > > >> > > > thread
> > > > >> > > > > > and
> > > > >> > > > > > > > the
> > > > >> > > > > > > > > > >> server
> > > > >> > > > > > > > > > >> > >> > doesn't
> > > > >> > > > > > > > > > >> > >> > > > > know which thread on the client
> > > side do
> > > > >> this
> > > > >> > > > cache
> > > > >> > > > > > > > > > >> operation).
> > > > >> > > > > > > > > > >> > In
> > > > >> > > > > > > > > > >> > >> my
> > > > >> > > > > > > > > > >> > >> > > > > opinion, if a user wants to use
> > > > >> concurrent
> > > > >> > > > > > > > transactions,
> > > > >> > > > > > > > > he
> > > > >> > > > > > > > > > >> must
> > > > >> > > > > > > > > > >> > >> use
> > > > >> > > > > > > > > > >> > >> > > > > different connections from a
> > > connection
> > > > >> pool.
> > > > >> > > > > > > > > > >> > >> > > > >
> > > > >> > > > > > > > > > >> > >> > > > > About semantics of
> suspend/resume
> > > on the
> > > > >> > > > > > client-side:
> > > > >> > > > > > > > > it's
> > > > >> > > > > > > > > > >> > >> absolutely
> > > > >> > > > > > > > > > >> > >> > > > > different than server-side
> > > semantics (we
> > > > >> > > don't
> > > > >> > > > need
> > > > >> > > > > > > to
> > > > >> > > > > > > > do
> > > > >> > > > > > > > > > >> > >> > > suspend/resume
> > > > >> > > > > > > > > > >> > >> > > > to
> > > > >> > > > > > > > > > >> > >> > > > > pass transaction between
> threads on
> > > the
> > > > >> > > > > > client-side),
> > > > >> > > > > > > > but
> > > > >> > > > > > > > > > >> can't
> > > > >> > > > > > > > > > >> > be
> > > > >> > > > > > > > > > >> > >> > > > > implemented efficiently without
> > > > >> implemented
> > > > >> > > > > > > > > suspend/resume on
> > > > >> > > > > > > > > > >> > >> > > > server-side.
> > > > >> > > > > > > > > > >> > >> > > > >
> > > > >> > > > > > > > > > >> > >> > > > > Can anyone give me permissions
> to
> > > > >> create IEP
> > > > >> > > on
> > > > >> > > > > > > Apache
> > > > >> > > > > > > > > wiki?
> > > > >> > > > > > > > > > >> > >> > > > >
> > > > >> > > > > > > > > > >> > >> > > > > ср, 27 мар. 2019 г. в 11:59,
> > > Vladimir
> > > > >> Ozerov
> > > > >> > > <
> > > > >> > > > > > > > > > >> > >> vozerov@gridgain.com>:
> > > > >> > > > > > > > > > >> > >> > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > Hi Alex,
> > > > >> > > > > > > > > > >> > >> > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > My comments was only about the
> > > > >> protocol.
> > > > >> > > > Getting
> > > > >> > > > > > > > > current
> > > > >> > > > > > > > > > >> info
> > > > >> > > > > > > > > > >> > >> about
> > > > >> > > > > > > > > > >> > >> > > > > > transaction should be handled
> by
> > > the
> > > > >> client
> > > > >> > > > > > itself.
> > > > >> > > > > > > > It
> > > > >> > > > > > > > > is
> > > > >> > > > > > > > > > >> not
> > > > >> > > > > > > > > > >> > >> > > protocl's
> > > > >> > > > > > > > > > >> > >> > > > > > concern. Same about other
> APIs and
> > > > >> behavior
> > > > >> > > > in
> > > > >> > > > > > case
> > > > >> > > > > > > > > another
> > > > >> > > > > > > > > > >> > >> > > transaction
> > > > >> > > > > > > > > > >> > >> > > > > is
> > > > >> > > > > > > > > > >> > >> > > > > > attempted from the same
> thread.
> > > > >> > > > > > > > > > >> > >> > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > Putting protocol aside,
> > > transaction
> > > > >> support
> > > > >> > > > is
> > > > >> > > > > > > > > complicated
> > > > >> > > > > > > > > > >> > >> matter.
> > > > >> > > > > > > > > > >> > >> > I
> > > > >> > > > > > > > > > >> > >> > > > > would
> > > > >> > > > > > > > > > >> > >> > > > > > propose to route through IEP
> and
> > > wide
> > > > >> > > > community
> > > > >> > > > > > > > > > >> discussion. We
> > > > >> > > > > > > > > > >> > >> need
> > > > >> > > > > > > > > > >> > >> > > to
> > > > >> > > > > > > > > > >> > >> > > > > > review API and semantics very
> > > > >> carefully,
> > > > >> > > > taking
> > > > >> > > > > > > > > > >> SUSPEND/RESUME
> > > > >> > > > > > > > > > >> > >> in
> > > > >> > > > > > > > > > >> > >> > > > count.
> > > > >> > > > > > > > > > >> > >> > > > > > Also I do not see how we
> support
> > > > >> client
> > > > >> > > > > > > transactions
> > > > >> > > > > > > > > > >> > efficiently
> > > > >> > > > > > > > > > >> > >> > > > without
> > > > >> > > > > > > > > > >> > >> > > > > > decoupling transactions from
> > > threads
> > > > >> on the
> > > > >> > > > > > server
> > > > >> > > > > > > > side
> > > > >> > > > > > > > > > >> first.
> > > > >> > > > > > > > > > >> > >> > > Because
> > > > >> > > > > > > > > > >> > >> > > > > > without it you will need a
> > > dedicated
> > > > >> server
> > > > >> > > > > > thread
> > > > >> > > > > > > > for
> > > > >> > > > > > > > > > >> every
> > > > >> > > > > > > > > > >> > >> > client's
> > > > >> > > > > > > > > > >> > >> > > > > > transaction which is slow and
> may
> > > even
> > > > >> > > crash
> > > > >> > > > the
> > > > >> > > > > > > > > server.
> > > > >> > > > > > > > > > >> > >> > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > Vladimir.
> > > > >> > > > > > > > > > >> > >> > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > On Wed, Mar 27, 2019 at 11:44
> AM
> > > Alex
> > > > >> > > > Plehanov <
> > > > >> > > > > > > > > > >> > >> > > > plehanov.alex@gmail.com>
> > > > >> > > > > > > > > > >> > >> > > > > > wrote:
> > > > >> > > > > > > > > > >> > >> > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > Vladimir, what if we want
> to get
> > > > >> current
> > > > >> > > > > > > > transaction
> > > > >> > > > > > > > > info
> > > > >> > > > > > > > > > >> > >> (tx()
> > > > >> > > > > > > > > > >> > >> > > > > method)?
> > > > >> > > > > > > > > > >> > >> > > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > Does close() method mapped
> to
> > > > >> > > > TX_END(rollback)?
> > > > >> > > > > > > > > > >> > >> > > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > For example, this code:
> > > > >> > > > > > > > > > >> > >> > > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > try(tx = txStart()) {
> > > > >> > > > > > > > > > >> > >> > > > > > >     tx.commit();
> > > > >> > > > > > > > > > >> > >> > > > > > > }
> > > > >> > > > > > > > > > >> > >> > > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > Will produce:
> > > > >> > > > > > > > > > >> > >> > > > > > > TX_START
> > > > >> > > > > > > > > > >> > >> > > > > > > TX_END(commit)
> > > > >> > > > > > > > > > >> > >> > > > > > > TX_END(rollback)
> > > > >> > > > > > > > > > >> > >> > > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > Am I understand you right?
> > > > >> > > > > > > > > > >> > >> > > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > About xid. There is yet
> another
> > > > >> proposal.
> > > > >> > > > Use
> > > > >> > > > > > > some
> > > > >> > > > > > > > > unique
> > > > >> > > > > > > > > > >> > per
> > > > >> > > > > > > > > > >> > >> > > > > connection
> > > > >> > > > > > > > > > >> > >> > > > > > id
> > > > >> > > > > > > > > > >> > >> > > > > > > (integer, simple counter)
> for
> > > > >> identifying
> > > > >> > > > the
> > > > >> > > > > > > > > > >> transaction on
> > > > >> > > > > > > > > > >> > >> > > > > > > commit/rollback message. The
> > > client
> > > > >> gets
> > > > >> > > > this
> > > > >> > > > > > id
> > > > >> > > > > > > > > from the
> > > > >> > > > > > > > > > >> > >> server
> > > > >> > > > > > > > > > >> > >> > > with
> > > > >> > > > > > > > > > >> > >> > > > > > > transaction info and sends
> it
> > > back
> > > > >> to the
> > > > >> > > > > > server
> > > > >> > > > > > > > when
> > > > >> > > > > > > > > > >> trying
> > > > >> > > > > > > > > > >> > >> to
> > > > >> > > > > > > > > > >> > >> > > > > > > commit/rollback transaction.
> > > This
> > > > >> id is
> > > > >> > > not
> > > > >> > > > > > shown
> > > > >> > > > > > > > to
> > > > >> > > > > > > > > > >> users.
> > > > >> > > > > > > > > > >> > >> But
> > > > >> > > > > > > > > > >> > >> > > also
> > > > >> > > > > > > > > > >> > >> > > > we
> > > > >> > > > > > > > > > >> > >> > > > > > can
> > > > >> > > > > > > > > > >> > >> > > > > > > pass from server to client
> real
> > > > >> > > > transaction id
> > > > >> > > > > > > > (xid)
> > > > >> > > > > > > > > with
> > > > >> > > > > > > > > > >> > >> > > transaction
> > > > >> > > > > > > > > > >> > >> > > > > > info
> > > > >> > > > > > > > > > >> > >> > > > > > > for diagnostic purposes.
> > > > >> > > > > > > > > > >> > >> > > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > And one more question: what
> > > should
> > > > >> we do
> > > > >> > > > if the
> > > > >> > > > > > > > > client
> > > > >> > > > > > > > > > >> > starts
> > > > >> > > > > > > > > > >> > >> a
> > > > >> > > > > > > > > > >> > >> > new
> > > > >> > > > > > > > > > >> > >> > > > > > > transaction without ending
> the
> > > old
> > > > >> one?
> > > > >> > > > Should
> > > > >> > > > > > we
> > > > >> > > > > > > > > end the
> > > > >> > > > > > > > > > >> > old
> > > > >> > > > > > > > > > >> > >> > > > > transaction
> > > > >> > > > > > > > > > >> > >> > > > > > > implicitly (rollback) or
> throw
> > > an
> > > > >> > > > exception to
> > > > >> > > > > > > the
> > > > >> > > > > > > > > > >> client?
> > > > >> > > > > > > > > > >> > In
> > > > >> > > > > > > > > > >> > >> my
> > > > >> > > > > > > > > > >> > >> > > > > opinion,
> > > > >> > > > > > > > > > >> > >> > > > > > > the first option is better.
> For
> > > > >> example,
> > > > >> > > > if we
> > > > >> > > > > > > got
> > > > >> > > > > > > > a
> > > > >> > > > > > > > > > >> > >> previously
> > > > >> > > > > > > > > > >> > >> > > used
> > > > >> > > > > > > > > > >> > >> > > > > > > connection from the
> connection
> > > > >> pool, we
> > > > >> > > > should
> > > > >> > > > > > > not
> > > > >> > > > > > > > > worry
> > > > >> > > > > > > > > > >> > about
> > > > >> > > > > > > > > > >> > >> > any
> > > > >> > > > > > > > > > >> > >> > > > > > > uncompleted transaction
> started
> > > by
> > > > >> the
> > > > >> > > > previous
> > > > >> > > > > > > > user
> > > > >> > > > > > > > > of
> > > > >> > > > > > > > > > >> this
> > > > >> > > > > > > > > > >> > >> > > > > connection.
> > > > >> > > > > > > > > > >> > >> > > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > ср, 27 мар. 2019 г. в 11:02,
> > > > >> Vladimir
> > > > >> > > > Ozerov <
> > > > >> > > > > > > > > > >> > >> > vozerov@gridgain.com
> > > > >> > > > > > > > > > >> > >> > > >:
> > > > >> > > > > > > > > > >> > >> > > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > As far as
> > > > >> SUSPEND/RESUME/SAVEPOINT - we
> > > > >> > > > do
> > > > >> > > > > > not
> > > > >> > > > > > > > > support
> > > > >> > > > > > > > > > >> > them
> > > > >> > > > > > > > > > >> > >> > yet,
> > > > >> > > > > > > > > > >> > >> > > > and
> > > > >> > > > > > > > > > >> > >> > > > > > > adding
> > > > >> > > > > > > > > > >> > >> > > > > > > > them in future should not
> > > > >> conflict with
> > > > >> > > > > > simple
> > > > >> > > > > > > > > > >> START/END
> > > > >> > > > > > > > > > >> > >> > > > > > infrastructure.
> > > > >> > > > > > > > > > >> > >> > > > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > On Wed, Mar 27, 2019 at
> 11:00
> > > AM
> > > > >> > > Vladimir
> > > > >> > > > > > > Ozerov
> > > > >> > > > > > > > <
> > > > >> > > > > > > > > > >> > >> > > > > vozerov@gridgain.com
> > > > >> > > > > > > > > > >> > >> > > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > wrote:
> > > > >> > > > > > > > > > >> > >> > > > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > > Hi Alex,
> > > > >> > > > > > > > > > >> > >> > > > > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > > I am not sure we need 5
> > > > >> commands.
> > > > >> > > > Wouldn't
> > > > >> > > > > > it
> > > > >> > > > > > > > be
> > > > >> > > > > > > > > > >> enough
> > > > >> > > > > > > > > > >> > to
> > > > >> > > > > > > > > > >> > >> > have
> > > > >> > > > > > > > > > >> > >> > > > > only
> > > > >> > > > > > > > > > >> > >> > > > > > > two?
> > > > >> > > > > > > > > > >> > >> > > > > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > > START - accepts optional
> > > > >> parameters,
> > > > >> > > > > > returns
> > > > >> > > > > > > > > > >> transaction
> > > > >> > > > > > > > > > >> > >> info
> > > > >> > > > > > > > > > >> > >> > > > > > > > > END - provides commit
> flag,
> > > > >> returns
> > > > >> > > > void
> > > > >> > > > > > > > > > >> > >> > > > > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > > Vladimir.
> > > > >> > > > > > > > > > >> > >> > > > > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > > On Wed, Mar 27, 2019 at
> > > 8:26 AM
> > > > >> Alex
> > > > >> > > > > > > Plehanov <
> > > > >> > > > > > > > > > >> > >> > > > > > plehanov.alex@gmail.com
> > > > >> > > > > > > > > > >> > >> > > > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > > wrote:
> > > > >> > > > > > > > > > >> > >> > > > > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> Sergey, yes, the close
> is
> > > > >> something
> > > > >> > > > like
> > > > >> > > > > > > > silent
> > > > >> > > > > > > > > > >> > rollback.
> > > > >> > > > > > > > > > >> > >> > But
> > > > >> > > > > > > > > > >> > >> > > we
> > > > >> > > > > > > > > > >> > >> > > > > can
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> also implement this on
> the
> > > > >> client
> > > > >> > > > side,
> > > > >> > > > > > just
> > > > >> > > > > > > > > using
> > > > >> > > > > > > > > > >> > >> rollback
> > > > >> > > > > > > > > > >> > >> > > and
> > > > >> > > > > > > > > > >> > >> > > > > > > ignoring
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> errors in the response.
> > > > >> > > > > > > > > > >> > >> > > > > > > > >>
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> ср, 27 мар. 2019 г. в
> > > 00:04,
> > > > >> Sergey
> > > > >> > > > > > Kozlov <
> > > > >> > > > > > > > > > >> > >> > > > skozlov@gridgain.com
> > > > >> > > > > > > > > > >> > >> > > > > >:
> > > > >> > > > > > > > > > >> > >> > > > > > > > >>
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > Nikolay
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > Am I correctly
> > > understand you
> > > > >> > > > points:
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> >    - close: rollback
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> >    - commit, close:
> do
> > > > >> nothing
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> >    - rollback,
> close: do
> > > > >> what? (I
> > > > >> > > > > > suppose
> > > > >> > > > > > > > > nothing)
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > Also you assume that
> > > after
> > > > >> > > > > > commit/rollback
> > > > >> > > > > > > > we
> > > > >> > > > > > > > > may
> > > > >> > > > > > > > > > >> > need
> > > > >> > > > > > > > > > >> > >> to
> > > > >> > > > > > > > > > >> > >> > > free
> > > > >> > > > > > > > > > >> > >> > > > > > some
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > resources on server
> > > > >> node(s)or just
> > > > >> > > > do on
> > > > >> > > > > > > > > client
> > > > >> > > > > > > > > > >> > started
> > > > >> > > > > > > > > > >> > >> > TX?
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > On Tue, Mar 26, 2019
> at
> > > > >> 10:41 PM
> > > > >> > > > Alex
> > > > >> > > > > > > > > Plehanov <
> > > > >> > > > > > > > > > >> > >> > > > > > > > plehanov.alex@gmail.com
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > wrote:
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > Sergey, we have the
> > > close()
> > > > >> > > > method in
> > > > >> > > > > > > the
> > > > >> > > > > > > > > thick
> > > > >> > > > > > > > > > >> > >> client,
> > > > >> > > > > > > > > > >> > >> > > it's
> > > > >> > > > > > > > > > >> > >> > > > > > > > behavior
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> is
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > slightly different
> than
> > > > >> > > rollback()
> > > > >> > > > > > > method
> > > > >> > > > > > > > > (it
> > > > >> > > > > > > > > > >> > should
> > > > >> > > > > > > > > > >> > >> > > > rollback
> > > > >> > > > > > > > > > >> > >> > > > > if
> > > > >> > > > > > > > > > >> > >> > > > > > > the
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > transaction is not
> > > > >> committed and
> > > > >> > > > do
> > > > >> > > > > > > > nothing
> > > > >> > > > > > > > > if
> > > > >> > > > > > > > > > >> the
> > > > >> > > > > > > > > > >> > >> > > > transaction
> > > > >> > > > > > > > > > >> > >> > > > > > is
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> already
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > committed). I
> think we
> > > > >> should
> > > > >> > > > support
> > > > >> > > > > > > > > > >> > >> try-with-resource
> > > > >> > > > > > > > > > >> > >> > > > > > semantics
> > > > >> > > > > > > > > > >> > >> > > > > > > in
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> the
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > thin client and
> > > > >> OP_TX_CLOSE will
> > > > >> > > > be
> > > > >> > > > > > > useful
> > > > >> > > > > > > > > here.
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > Nikolay,
> suspend/resume
> > > > >> didn't
> > > > >> > > > work
> > > > >> > > > > > yet
> > > > >> > > > > > > > for
> > > > >> > > > > > > > > > >> > >> pessimistic
> > > > >> > > > > > > > > > >> > >> > > > > > > > transactions.
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > Also,
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > the main goal of
> > > > >> suspend/resume
> > > > >> > > > > > > operations
> > > > >> > > > > > > > > is to
> > > > >> > > > > > > > > > >> > >> support
> > > > >> > > > > > > > > > >> > >> > > > > > > transaction
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > passing between
> > > threads.
> > > > >> In the
> > > > >> > > > thin
> > > > >> > > > > > > > > client, the
> > > > >> > > > > > > > > > >> > >> > > transaction
> > > > >> > > > > > > > > > >> > >> > > > > is
> > > > >> > > > > > > > > > >> > >> > > > > > > > bound
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> to
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > the client
> connection,
> > > not
> > > > >> > > client
> > > > >> > > > > > > thread.
> > > > >> > > > > > > > I
> > > > >> > > > > > > > > > >> think
> > > > >> > > > > > > > > > >> > >> > passing
> > > > >> > > > > > > > > > >> > >> > > a
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> transaction
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > between different
> > > client
> > > > >> > > > connections
> > > > >> > > > > > is
> > > > >> > > > > > > > not
> > > > >> > > > > > > > > a
> > > > >> > > > > > > > > > >> very
> > > > >> > > > > > > > > > >> > >> > useful
> > > > >> > > > > > > > > > >> > >> > > > > case.
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > вт, 26 мар. 2019
> г. в
> > > > >> 22:17,
> > > > >> > > > Nikolay
> > > > >> > > > > > > > > Izhikov <
> > > > >> > > > > > > > > > >> > >> > > > > > nizhikov@apache.org
> > > > >> > > > > > > > > > >> > >> > > > > > > >:
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > Hello, Alex.
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > We also have
> suspend
> > > and
> > > > >> > > resume
> > > > >> > > > > > > > > operations.
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > I think we should
> > > > >> support them
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > вт, 26 марта
> 2019 г.,
> > > > >> 22:07
> > > > >> > > > Sergey
> > > > >> > > > > > > > Kozlov
> > > > >> > > > > > > > > <
> > > > >> > > > > > > > > > >> > >> > > > > > skozlov@gridgain.com
> > > > >> > > > > > > > > > >> > >> > > > > > > >:
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > Hi
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > Looks like I
> missed
> > > > >> > > something
> > > > >> > > > but
> > > > >> > > > > > > why
> > > > >> > > > > > > > we
> > > > >> > > > > > > > > > >> need
> > > > >> > > > > > > > > > >> > >> > > > OP_TX_CLOSE
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> operation?
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > Also I suggest
> to
> > > > >> reserve a
> > > > >> > > > code
> > > > >> > > > > > for
> > > > >> > > > > > > > > > >> SAVEPOINT
> > > > >> > > > > > > > > > >> > >> > > operation
> > > > >> > > > > > > > > > >> > >> > > > > > which
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> very
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > useful
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > to understand
> where
> > > > >> > > > transaction
> > > > >> > > > > > has
> > > > >> > > > > > > > been
> > > > >> > > > > > > > > > >> rolled
> > > > >> > > > > > > > > > >> > >> back
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > On Tue, Mar 26,
> > > 2019
> > > > >> at 6:07
> > > > >> > > > PM
> > > > >> > > > > > Alex
> > > > >> > > > > > > > > > >> Plehanov <
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> >
> plehanov.alex@gmail.com
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > wrote:
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > Hello
> Igniters!
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > I want to
> pick
> > > up the
> > > > >> > > ticket
> > > > >> > > > > > > > > IGNITE-7369
> > > > >> > > > > > > > > > >> and
> > > > >> > > > > > > > > > >> > >> add
> > > > >> > > > > > > > > > >> > >> > > > > > > transactions
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > support
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > to
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > our thin
> client
> > > > >> > > > implementation.
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > I've looked
> at
> > > our
> > > > >> current
> > > > >> > > > > > > > > implementation
> > > > >> > > > > > > > > > >> and
> > > > >> > > > > > > > > > >> > >> have
> > > > >> > > > > > > > > > >> > >> > > > some
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> proposals
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > to
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > support
> > > transactions:
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > Add new
> > > operations
> > > > >> to thin
> > > > >> > > > > > client
> > > > >> > > > > > > > > > >> protocol:
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
>  OP_TX_GET,
> > > 4000,
> > > > >> Get
> > > > >> > > > current
> > > > >> > > > > > > > > > >> transaction
> > > > >> > > > > > > > > > >> > >> for
> > > > >> > > > > > > > > > >> > >> > > > client
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> connection
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
>  OP_TX_START,
> > > > >> 4001,
> > > > >> > > > Start a
> > > > >> > > > > > new
> > > > >> > > > > > > > > > >> > transaction
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
>  OP_TX_COMMIT,
> > > > >> 4002,
> > > > >> > > > Commit
> > > > >> > > > > > > > > transaction
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
> > >  OP_TX_ROLLBACK,
> > > > >> 4003,
> > > > >> > > > > > Rollback
> > > > >> > > > > > > > > > >> > transaction
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
>  OP_TX_CLOSE,
> > > > >> 4004,
> > > > >> > > Close
> > > > >> > > > > > > > > transaction
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > From the
> client
> > > side
> > > > >> > > (java)
> > > > >> > > > new
> > > > >> > > > > > > > > interfaces
> > > > >> > > > > > > > > > >> > >> will be
> > > > >> > > > > > > > > > >> > >> > > > > added:
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > public
> interface
> > > > >> > > > > > > ClientTransactions
> > > > >> > > > > > > > {
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >     public
> > > > >> > > ClientTransaction
> > > > >> > > > > > > > > txStart();
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >     public
> > > > >> > > ClientTransaction
> > > > >> > > > > > > > > > >> > >> > > > > > txStart(TransactionConcurrency
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > concurrency,
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
> > > TransactionIsolation
> > > > >> > > > isolation);
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >     public
> > > > >> > > ClientTransaction
> > > > >> > > > > > > > > > >> > >> > > > > > txStart(TransactionConcurrency
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > concurrency,
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
> > > TransactionIsolation
> > > > >> > > > isolation,
> > > > >> > > > > > > long
> > > > >> > > > > > > > > > >> timeout,
> > > > >> > > > > > > > > > >> > >> int
> > > > >> > > > > > > > > > >> > >> > > > > txSize);
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >     public
> > > > >> > > ClientTransaction
> > > > >> > > > > > tx();
> > > > >> > > > > > > > //
> > > > >> > > > > > > > > Get
> > > > >> > > > > > > > > > >> > >> current
> > > > >> > > > > > > > > > >> > >> > > > > > connection
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > transaction
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >     public
> > > > >> > > > ClientTransactions
> > > > >> > > > > > > > > > >> > withLabel(String
> > > > >> > > > > > > > > > >> > >> > lb);
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > }
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > public
> interface
> > > > >> > > > > > ClientTransaction
> > > > >> > > > > > > > > extends
> > > > >> > > > > > > > > > >> > >> > > > > AutoCloseable {
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >     public
> > > IgniteUuid
> > > > >> > > > xid(); //
> > > > >> > > > > > Do
> > > > >> > > > > > > > we
> > > > >> > > > > > > > > need
> > > > >> > > > > > > > > > >> > it?
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >     public
> > > > >> > > > TransactionIsolation
> > > > >> > > > > > > > > > >> isolation();
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >     public
> > > > >> > > > > > TransactionConcurrency
> > > > >> > > > > > > > > > >> > >> concurrency();
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >     public
> long
> > > > >> timeout();
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >     public
> String
> > > > >> label();
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >     public
> void
> > > > >> commit();
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >     public
> void
> > > > >> > > rollback();
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >     public
> void
> > > > >> close();
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > }
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > From the
> server
> > > > >> side, I
> > > > >> > > > think
> > > > >> > > > > > as a
> > > > >> > > > > > > > > first
> > > > >> > > > > > > > > > >> step
> > > > >> > > > > > > > > > >> > >> > (while
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> transactions
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
> suspend/resume
> > > is not
> > > > >> > > fully
> > > > >> > > > > > > > > implemented)
> > > > >> > > > > > > > > > >> we
> > > > >> > > > > > > > > > >> > can
> > > > >> > > > > > > > > > >> > >> > use
> > > > >> > > > > > > > > > >> > >> > > > the
> > > > >> > > > > > > > > > >> > >> > > > > > same
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > approach
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > as
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > for JDBC:
> add a
> > > new
> > > > >> worker
> > > > >> > > > to
> > > > >> > > > > > each
> > > > >> > > > > > > > > > >> > >> > > > ClientRequestHandler
> > > > >> > > > > > > > > > >> > >> > > > > > and
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> process
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > requests by
> this
> > > > >> worker if
> > > > >> > > > the
> > > > >> > > > > > > > > > >> transaction is
> > > > >> > > > > > > > > > >> > >> > > started
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> explicitly.
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
> > > ClientRequestHandler
> > > > >> is
> > > > >> > > > bound to
> > > > >> > > > > > > > > client
> > > > >> > > > > > > > > > >> > >> > connection,
> > > > >> > > > > > > > > > >> > >> > > so
> > > > >> > > > > > > > > > >> > >> > > > > > there
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> will
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > be
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > 1:1
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > relation
> between
> > > > >> client
> > > > >> > > > > > connection
> > > > >> > > > > > > > and
> > > > >> > > > > > > > > > >> > thread,
> > > > >> > > > > > > > > > >> > >> > which
> > > > >> > > > > > > > > > >> > >> > > > > > process
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > operations
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > in
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > a
> transaction.
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > Also, there
> is a
> > > > >> couple of
> > > > >> > > > > > issues
> > > > >> > > > > > > I
> > > > >> > > > > > > > > want
> > > > >> > > > > > > > > > >> to
> > > > >> > > > > > > > > > >> > >> > discuss:
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > >
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > We have
> > > overloaded
> > > > >> method
> > > > >> > > > > > txStart
> > > > >> > > > > > > > > with a
> > > > >> > > > > > > > > > >> > >> different
> > > > >> > > > > > > > > > >> > >> > > set
> > > > >> > > > > > > > > > >> > >> > > > > of
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > arguments.
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > Some
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> > > > > > of the
> arguments
> > > may
> > > > >> be
> > > > >> > > > missing.
> > > > >> > > > > > > To
> > > > >> > > > > > > > > pass
> > > > >> > > > > > > > > > >> > >> arguments
> > > > >> > > > > > > > > > >> > >> > > > with
> > > > >> > > > > > > > > > >> > >> > > > > > > > >> OP_TX_START
> > > > >> > > > > > > > > > >> > >> &
> > > > >
> > > > >
> > >
> > >
> > >
> > > --
> > > Best regards,
> > > Ivan Pavlukhin
> > >
>
>
>
> --
> Best regards,
> Ivan Pavlukhin
>

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