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From Igor Sapego <isap...@apache.org>
Subject Re: Thin client: transactions support
Date Mon, 20 May 2019 12:24:06 GMT
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
> > > > > > > >> > >> > > > > > > > >> > > > > > 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
> > > > > > > >> > >> > > > > > > > >> >
> > > > > > > >> > >> > > > > > > > >>
> > > > > > > >> > >> > > > > > > > >
> > > > > > > >> > >> > > > > > > >
> > > > > > > >> > >> > > > > > >
> > > > > > > >> > >> > > > > >
> > > > > > > >> > >> > > > >
> > > > > > > >> > >> > > >
> > > > > > > >> > >> > >
> > > > > > > >> > >> >
> > > > > > > >> > >>
> > > > > > > >> > >
> > > > > > > >> >
> > > > > > > >>
> > > > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > --
> > > > > > Best regards,
> > > > > > Ivan Pavlukhin
> > > > > >
> > > > > >
> > > > >
> > > >
> > >
>
>
>
> --
> Best regards,
> Ivan Pavlukhin
>

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