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From Alex Plehanov <plehanov.a...@gmail.com>
Subject Re: Thin client: transactions support
Date Thu, 04 Apr 2019 08:32:56 GMT
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
> > >> > > > > > > > >> > > > > > operation we have the next options:
> > >> > > > > > > > >> > > > > >  * Serialize full set of arguments and use
> > some
> > >> > > value
> > >> > > > > for
> > >> > > > > > > > >> missing
> > >> > > > > > > > >> > > > > > arguments. For example -1 for int/long
> types
> > >> and
> > >> > > null
> > >> > > > > for
> > >> > > > > > > > string
> > >> > > > > > > > >> > > type.
> > >> > > > > > > > >> > > > We
> > >> > > > > > > > >> > > > > > can't use 0 for int/long types since 0
> it's a
> > >> > valid
> > >> > > > > value
> > >> > > > > > > for
> > >> > > > > > > > >> > > > > concurrency,
> > >> > > > > > > > >> > > > > > isolation and timeout arguments.
> > >> > > > > > > > >> > > > > >  * Serialize arguments as a collection of
> > >> > > > property-value
> > >> > > > > > > pairs
> > >> > > > > > > > >> > (like
> > >> > > > > > > > >> > > > it's
> > >> > > > > > > > >> > > > > > implemented now for CacheConfiguration). In
> > >> this
> > >> > > case
> > >> > > > > only
> > >> > > > > > > > >> > explicitly
> > >> > > > > > > > >> > > > > > provided arguments will be serialized.
> > >> > > > > > > > >> > > > > > Which way is better? The simplest solution
> is
> > >> to
> > >> > use
> > >> > > > the
> > >> > > > > > > first
> > >> > > > > > > > >> > option
> > >> > > > > > > > >> > > > > and I
> > >> > > > > > > > >> > > > > > want to use it if there were no objections.
> > >> > > > > > > > >> > > > > >
> > >> > > > > > > > >> > > > > > Do we need transaction id (xid) on the
> client
> > >> > side?
> > >> > > > > > > > >> > > > > > If yes, we can pass xid along with
> > >> OP_TX_COMMIT,
> > >> > > > > > > > OP_TX_ROLLBACK,
> > >> > > > > > > > >> > > > > > OP_TX_CLOSE operations back to the server
> and
> > >> do
> > >> > > > > > additional
> > >> > > > > > > > >> check
> > >> > > > > > > > >> > on
> > >> > > > > > > > >> > > > the
> > >> > > > > > > > >> > > > > > server side (current transaction id for
> > >> connection
> > >> > > ==
> > >> > > > > > > > >> transaction
> > >> > > > > > > > >> > id
> > >> > > > > > > > >> > > > > passed
> > >> > > > > > > > >> > > > > > from client side). This, perhaps, will
> > protect
> > >> > > clients
> > >> > > > > > > against
> > >> > > > > > > > >> some
> > >> > > > > > > > >> > > > > errors
> > >> > > > > > > > >> > > > > > (for example when client try to commit
> > outdated
> > >> > > > > > > transaction).
> > >> > > > > > > > >> But
> > >> > > > > > > > >> > > > > > currently, we don't have data type
> IgniteUuid
> > >> in
> > >> > > thin
> > >> > > > > > client
> > >> > > > > > > > >> > > protocol.
> > >> > > > > > > > >> > > > Do
> > >> > > > > > > > >> > > > > > we need to add it too?
> > >> > > > > > > > >> > > > > > Also, we can pass xid as a string just to
> > >> inform
> > >> > the
> > >> > > > > > client
> > >> > > > > > > > and
> > >> > > > > > > > >> do
> > >> > > > > > > > >> > > not
> > >> > > > > > > > >> > > > > pass
> > >> > > > > > > > >> > > > > > it back to the server with commit/rollback
> > >> > > operation.
> > >> > > > > > > > >> > > > > > Or not to pass xid at all (.NET thick
> client
> > >> works
> > >> > > > this
> > >> > > > > > way
> > >> > > > > > > as
> > >> > > > > > > > >> far
> > >> > > > > > > > >> > > as I
> > >> > > > > > > > >> > > > > > know).
> > >> > > > > > > > >> > > > > >
> > >> > > > > > > > >> > > > > > What do you think?
> > >> > > > > > > > >> > > > > >
> > >> > > > > > > > >> > > > > > ср, 7 мар. 2018 г. в 16:22, Vladimir
> Ozerov <
> > >> > > > > > > > >> vozerov@gridgain.com
> > >> > > > > > > > >> > >:
> > >> > > > > > > > >> > > > > >
> > >> > > > > > > > >> > > > > > > We already have transactions support in
> > JDBC
> > >> > > driver
> > >> > > > in
> > >> > > > > > TX
> > >> > > > > > > > SQL
> > >> > > > > > > > >> > > branch
> > >> > > > > > > > >> > > > > > > (ignite-4191). Currently it is
> implemented
> > >> > through
> > >> > > > > > > separate
> > >> > > > > > > > >> > thread,
> > >> > > > > > > > >> > > > > which
> > >> > > > > > > > >> > > > > > > is not that efficient. Ideally we need to
> > >> finish
> > >> > > > > > > decoupling
> > >> > > > > > > > >> > > > > transactions
> > >> > > > > > > > >> > > > > > > from threads. But alternatively we can
> > change
> > >> > the
> > >> > > > > logic
> > >> > > > > > on
> > >> > > > > > > > >> how we
> > >> > > > > > > > >> > > > > assign
> > >> > > > > > > > >> > > > > > > thread ID to specific transaction and
> > >> > > "impersonate"
> > >> > > > > thin
> > >> > > > > > > > >> client
> > >> > > > > > > > >> > > > worker
> > >> > > > > > > > >> > > > > > > threads when serving requests from
> multiple
> > >> > users.
> > >> > > > > > > > >> > > > > > >
> > >> > > > > > > > >> > > > > > >
> > >> > > > > > > > >> > > > > > >
> > >> > > > > > > > >> > > > > > > On Tue, Mar 6, 2018 at 10:01 PM, Denis
> > Magda
> > >> <
> > >> > > > > > > > >> dmagda@apache.org>
> > >> > > > > > > > >> > > > > wrote:
> > >> > > > > > > > >> > > > > > >
> > >> > > > > > > > >> > > > > > > > Here is an original discussion with a
> > >> > reference
> > >> > > to
> > >> > > > > the
> > >> > > > > > > > JIRA
> > >> > > > > > > > >> > > ticket:
> > >> > > > > > > > >> > > > > > > >
> > >> > > http://apache-ignite-developers.2346864.n4.nabble
> > >> > > > .
> > >> > > > > > > > >> > > > > > > >
> > >> > > > > > > >
> > com/Re-Transaction-operations-using-the-Ignite-Thin-Client-
> > >> > > > > > > > >> > > > > > > > Protocol-td25914.html
> > >> > > > > > > > >> > > > > > > >
> > >> > > > > > > > >> > > > > > > > --
> > >> > > > > > > > >> > > > > > > > Denis
> > >> > > > > > > > >> > > > > > > >
> > >> > > > > > > > >> > > > > > > > On Tue, Mar 6, 2018 at 9:18 AM, Dmitriy
> > >> > > Setrakyan
> > >> > > > <
> > >> > > > > > > > >> > > > > > dsetrakyan@apache.org
> > >> > > > > > > > >> > > > > > > >
> > >> > > > > > > > >> > > > > > > > wrote:
> > >> > > > > > > > >> > > > > > > >
> > >> > > > > > > > >> > > > > > > > > Hi Dmitriy. I don't think we have a
> > >> design
> > >> > > > > proposal
> > >> > > > > > > for
> > >> > > > > > > > >> > > > transaction
> > >> > > > > > > > >> > > > > > > > support
> > >> > > > > > > > >> > > > > > > > > in thin clients. Do you mind taking
> > this
> > >> > > > > initiative
> > >> > > > > > > and
> > >> > > > > > > > >> > > creating
> > >> > > > > > > > >> > > > an
> > >> > > > > > > > >> > > > > > IEP
> > >> > > > > > > > >> > > > > > > > on
> > >> > > > > > > > >> > > > > > > > > Wiki?
> > >> > > > > > > > >> > > > > > > > >
> > >> > > > > > > > >> > > > > > > > > D.
> > >> > > > > > > > >> > > > > > > > >
> > >> > > > > > > > >> > > > > > > > > On Tue, Mar 6, 2018 at 8:46 AM,
> Dmitriy
> > >> > > > > Govorukhin <
> > >> > > > > > > > >> > > > > > > > > dmitriy.govorukhin@gmail.com> wrote:
> > >> > > > > > > > >> > > > > > > > >
> > >> > > > > > > > >> > > > > > > > > > Hi, Igniters.
> > >> > > > > > > > >> > > > > > > > > >
> > >> > > > > > > > >> > > > > > > > > > I've seen a lot of discussions
> about
> > >> thin
> > >> > > > client
> > >> > > > > > and
> > >> > > > > > > > >> binary
> > >> > > > > > > > >> > > > > > protocol,
> > >> > > > > > > > >> > > > > > > > > but I
> > >> > > > > > > > >> > > > > > > > > > did not hear anything about
> > >> transactions
> > >> > > > > support.
> > >> > > > > > Do
> > >> > > > > > > > we
> > >> > > > > > > > >> > have
> > >> > > > > > > > >> > > > some
> > >> > > > > > > > >> > > > > > > draft
> > >> > > > > > > > >> > > > > > > > > for
> > >> > > > > > > > >> > > > > > > > > > this purpose?
> > >> > > > > > > > >> > > > > > > > > >
> > >> > > > > > > > >> > > > > > > > > > As I understand we have several
> > >> problems:
> > >> > > > > > > > >> > > > > > > > > >
> > >> > > > > > > > >> > > > > > > > > >    - thread and transaction have
> hard
> > >> > > related
> > >> > > > > (we
> > >> > > > > > > use
> > >> > > > > > > > >> > > > > thread-local
> > >> > > > > > > > >> > > > > > > > > variable
> > >> > > > > > > > >> > > > > > > > > >    and thread name)
> > >> > > > > > > > >> > > > > > > > > >    - we can process only one
> > >> transaction
> > >> > at
> > >> > > > the
> > >> > > > > > same
> > >> > > > > > > > >> time
> > >> > > > > > > > >> > in
> > >> > > > > > > > >> > > > one
> > >> > > > > > > > >> > > > > > > thread
> > >> > > > > > > > >> > > > > > > > > (it
> > >> > > > > > > > >> > > > > > > > > >    mean we need hold thread per
> > >> client. If
> > >> > > > > connect
> > >> > > > > > > 100
> > >> > > > > > > > >> thin
> > >> > > > > > > > >> > > > > clients
> > >> > > > > > > > >> > > > > > > to
> > >> > > > > > > > >> > > > > > > > 1
> > >> > > > > > > > >> > > > > > > > > >    server node, then need to hold
> 100
> > >> > thread
> > >> > > > on
> > >> > > > > > the
> > >> > > > > > > > >> server
> > >> > > > > > > > >> > > > side)
> > >> > > > > > > > >> > > > > > > > > >
> > >> > > > > > > > >> > > > > > > > > > Let's discuss how we can implement
> > >> > > > transactions
> > >> > > > > > for
> > >> > > > > > > > the
> > >> > > > > > > > >> > thin
> > >> > > > > > > > >> > > > > > client.
> > >> > > > > > > > >> > > > > > > > > >
> > >> > > > > > > > >> > > > > > > > >
> > >> > > > > > > > >> > > > > > > >
> > >> > > > > > > > >> > > > > > >
> > >> > > > > > > > >> > > > > >
> > >> > > > > > > > >> > > > >
> > >> > > > > > > > >> > > > >
> > >> > > > > > > > >> > > > > --
> > >> > > > > > > > >> > > > > Sergey Kozlov
> > >> > > > > > > > >> > > > > GridGain Systems
> > >> > > > > > > > >> > > > > www.gridgain.com
> > >> > > > > > > > >> > > > >
> > >> > > > > > > > >> > > >
> > >> > > > > > > > >> > >
> > >> > > > > > > > >> >
> > >> > > > > > > > >> >
> > >> > > > > > > > >> > --
> > >> > > > > > > > >> > Sergey Kozlov
> > >> > > > > > > > >> > GridGain Systems
> > >> > > > > > > > >> > www.gridgain.com
> > >> > > > > > > > >> >
> > >> > > > > > > > >>
> > >> > > > > > > > >
> > >> > > > > > > >
> > >> > > > > > >
> > >> > > > > >
> > >> > > > >
> > >> > > >
> > >> > >
> > >> >
> > >>
> > >
> >
>

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