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From Anton Vinogradov ...@apache.org>
Subject Re: Ability to check and completely fill transactions on creation
Date Fri, 01 Jun 2018 19:59:00 GMT
Dmitriy,

Unfortunately, we have more than 2 types of txs, full list is

GridDhtTxLocal
GridDhtTxRemote
GridNearTxLocal
GridNearTxRemote

BTW, We have no clear documentation about behaviour and difference.
I created an issue [1] to solve this, but seems no one interested :(


1) What I see is that every Grid*Tx* have xid, startTime, isolation,
concurrency, etc. So, there is no difference in params.
Label is the only one exception to the rule, but this can be fixed.

So, every Grid*Tx* can provide it's params once it's state changed.
And it's a good Idea to have possibility to see state changes and tx params.

2) Other good idea is to have chance to rollback or resume or even commit
transaction inside tx event listener on each state change.
Currently "actions" available only from GridNearTxLocal events, but what's
the problem to allow rollback from GridDhtTxLocal in future?

3) Currently, each TransactionStateChangedEvent provides "Transaction tx"
which is special proxy for specific type of IgniteTxAdapter.
GridNearTxLocal's proxy is fully implemented, other implemented partially,
but can be improved later.

What about to add flags 'local', 'near', 'dht' and 'remote' to
TransactionStateChangedEvent to explain where state changed?
In case it's 'near | local' you'll have chances to rollback such tx.
In case it's 'dht | remote' you'll see what is the real last mile timeout
for txs at your system. It can be much smaller than initial tx timeout.
...

4) So, I propose to keep this design because it's good for *monitoring and
restrictions* and improve it on demand (no refactoring needed, just
implement cases throwing UnsupportedOperationException)
- new EVT_TX_* events can be added, eg. EVT_TX_PREPARING
- label can be shared to all txs (thats not a problem as I can see, and I
can do it as a separate task)
- rollback can be implemented on all Grid*TxLocal or even at Grid*TxRemote
:)

[1] https://issues.apache.org/jira/browse/IGNITE-8419

пт, 1 июн. 2018 г. в 19:35, Dmitriy Setrakyan <dsetrakyan@apache.org>:

> I do not like the inconsistent behavior between different transaction
> events. I now feel that we need to separate events between Near TX and
> Remote TX, and maybe focus on the Near TX for now.
>
> How about we only add events for the Near TX and have a consistent behavior
> across all Near TX events. I would suggest that you rename your event to
> EVT_TX_NEAR_STARTED/PREPARED/COMMITTED/etc/etc? In this case the "label()"
> method will always provide required data, right?
>
> D.
>
> On Fri, Jun 1, 2018 at 7:19 AM, Anton Vinogradov <av@apache.org> wrote:
>
> > Dmitriy,
> >
> > 1) EVT_TX_PREPARED were added this morning to check event generation on
> > remote nodes :)
> >
> > 2) Only GridNearTxLocal has label now, that's the implementation we
> > currently have. It can be improved if necesary, I think.
> > So, actually, label always available at
> > - EVT_TX_STARTED,
> > - EVT_TX_SUSPENDED,
> > - EVT_TX_RESUMED
> > since they can be fired only from originating node (from GridNearTxLocal)
> >
> > In case any other event will be fired by GridNearTxLocal it will contain
> > label too.
> > In case of user call label on remote event it will gain
> > UnsupportedOperationException.
> >
> > BTW, rollback also available only at events produced by GridNearTxLocal.
> >
> > пт, 1 июн. 2018 г. в 16:29, Dmitriy Setrakyan <dsetrakyan@apache.org>:
> >
> > > Ok, sounds good.
> > >
> > > I till have more comments:
> > >
> > >    1. I think you have missed EVT_TX_PREPARED event
> > >    2. I am still very confused with your comment on "label()" method.
> Why
> > >    is the label not propagated to remote nodes? What happens when users
> > > call
> > >    this "label()" method for other TX events, not the EVT_TX_STARTED
> > event?
> > >
> > > D.
> > >
> > > On Fri, Jun 1, 2018 at 6:20 AM, Anton Vinogradov <av@apache.org>
> wrote:
> > >
> > > > Dmitriy,
> > > >
> > > > In that case there will be no chances to listen only tx creation
> events
> > > > without slowing down the system on other tx events creation and
> > > filtering.
> > > > All events are processed at same thread where tx changes the state,
> so,
> > > we
> > > > have to have the way to decrease potential slowdown.
> > > >
> > > > I made it similar to
> > > >  public static final int[] EVTS_CACHE = {
> > > >         EVT_CACHE_ENTRY_CREATED,
> > > >         EVT_CACHE_ENTRY_DESTROYED,
> > > >         EVT_CACHE_OBJECT_PUT,
> > > >         EVT_CACHE_OBJECT_READ,
> > > >         EVT_CACHE_OBJECT_REMOVED,
> > > >         EVT_CACHE_OBJECT_LOCKED,
> > > >         EVT_CACHE_OBJECT_UNLOCKED,
> > > >         EVT_CACHE_OBJECT_EXPIRED
> > > >     };
> > > >
> > > >
> > > > чт, 31 мая 2018 г. в 20:48, Dmitriy Setrakyan <dsetrakyan@apache.org
> >:
> > > >
> > > > > Anton,
> > > > >
> > > > > Why not just have one transaction event: EVT_TX_STATE_CHANGED?
> > > > >
> > > > > D.
> > > > >
> > > > > On Thu, May 31, 2018 at 9:10 AM, Anton Vinogradov <av@apache.org>
> > > wrote:
> > > > >
> > > > > > Dmitriy,
> > > > > >
> > > > > > Thanks for your comments!
> > > > > >
> > > > > > I've updated design to have
> > > > > >
> > > > > > public class TransactionStateChangedEvent extends EventAdapter
{
> > > > > >     private Transaction tx;
> > > > > > }
> > > > > >
> > > > > > also I specified following set of possible events
> > > > > >
> > > > > > public static final int[] EVTS_TX = {
> > > > > > EVT_TX_STARTED,
> > > > > > EVT_TX_COMMITTED,
> > > > > > EVT_TX_ROLLED_BACK,
> > > > > > EVT_TX_SUSPENDED,
> > > > > > EVT_TX_RESUMED
> > > > > > };
> > > > > >
> > > > > > It contains most of reasonable tx states changes.
> > > > > > Additional events can be added later if necessary.
> > > > > >
> > > > > >
> > > > > > Tx label() available only at EVT_TX_STARTED because it is not
> > > > propagated
> > > > > to
> > > > > > remote nodes, but
> > > > > >
> > > > > > - xid()
> > > > > > - nodeId()
> > > > > > - threadId()
> > > > > > - startTime()
> > > > > > - isolation()
> > > > > > - concurrency()
> > > > > > - implicit()
> > > > > > - isInvalidate()
> > > > > > - state()
> > > > > > - timeout()
> > > > > >
> > > > > > now available at any tx state change event.
> > > > > >
> > > > > >
> > > > > > As usual, full code listing available at
> > > > > > https://github.com/apache/ignite/pull/4036/files
> > > > > >
> > > > > >
> > > > > > вт, 29 мая 2018 г. в 20:41, Dmitriy Setrakyan <
> > dsetrakyan@apache.org
> > > >:
> > > > > >
> > > > > > > Anton,
> > > > > > >
> > > > > > > We cannot have TransactionStartedEvent without having events
> for
> > > all
> > > > > > other
> > > > > > > transaction states, like TransactionPreparedEvent,
> > > > > > > TransactionCommittedEvent, etc. Considering this, I sill
do not
> > > like
> > > > > the
> > > > > > > design, as we would have to create many extra event classes.
> > > > > > >
> > > > > > > Instead, I would suggest that you create
> > > TransactionStateChangeEvent,
> > > > > > which
> > > > > > > would have previous and new transaction state and would
cover
> all
> > > > state
> > > > > > > changes, not just the start of the transaction. This will
make
> > the
> > > > > design
> > > > > > > consistent and thorough.
> > > > > > >
> > > > > > > D.
> > > > > > >
> > > > > > > On Tue, May 29, 2018 at 5:39 AM, Anton Vinogradov <
> av@apache.org
> > >
> > > > > wrote:
> > > > > > >
> > > > > > > > Dmitriy,
> > > > > > > > I fixed design according to your and Yakov's comments,
thanks
> > > again
> > > > > for
> > > > > > > > clear explanation.
> > > > > > > >
> > > > > > > > >> 1. You use internal API in public event,
i.e. you cannot
> > have
> > > > user
> > > > > > > > >> accessing to IgniteInternalTx instance through
TxEvent.
> > > > > > > >
> > > > > > > > Event definition changed to
> > > > > > > > public class TransactionStartedEvent extends EventAdapter
{
> > > > > > > >     private IgniteTransactions tx;
> > > > > > > > ...
> > > > > > > > }
> > > > > > > >
> > > > > > > > Not it's 100% public.
> > > > > > > >
> > > > > > > > >> 2. Throwing runtime errors from listener
is not documented
> > > and I
> > > > > > doubt
> > > > > > > > if
> > > > > > > > >> it can be fully supported in the pattern
you use in
> > > TxLabelTest.
> > > > > > After
> > > > > > > > >> looking at the mentioned test user may think
that throwing
> > > > runtime
> > > > > > > error
> > > > > > > > >> when notified on new node join may prohibit
new node
> joining
> > > > which
> > > > > > is
> > > > > > > > not
> > > > > > > > >> true. Do you have any example in Ignite when
throwing
> > > exception
> > > > > from
> > > > > > > > >> listener is valid and documented.
> > > > > > > >
> > > > > > > > Test's logic changed to
> > > > > > > > ...
> > > > > > > > // Label
> > > > > > > > IgniteTransactions tx = evt.tx();
> > > > > > > >
> > > > > > > > if (tx.label() == null)
> > > > > > > > tx.tx().rollback();
> > > > > > > > ...
> > > > > > > > and
> > > > > > > > ...
> > > > > > > > // Timeout
> > > > > > > > Transaction tx = evt.tx().tx();
> > > > > > > >
> > > > > > > > if (tx.timeout() < 200)
> > > > > > > > tx.rollback();
> > > > > > > > ...
> > > > > > > >
> > > > > > > > So, tx will be rollbacked on creation and any commit
attempt
> > will
> > > > > cause
> > > > > > > > TransactionRollbackException
> > > > > > > >
> > > > > > > > Full code listing available at
> > > > > > > > https://github.com/apache/ignite/pull/4036/files
> > > > > > > >
> > > > > > > > Dmitriy, Yakov,
> > > > > > > > Could you please check and confirm changes?
> > > > > > > >
> > > > > > > > чт, 24 мая 2018 г. в 16:32, Dmitriy Setrakyan
<
> > > > dsetrakyan@apache.org
> > > > > >:
> > > > > > > >
> > > > > > > > > Anton, why do you need to *alter* event sub-system
to
> > > introduce a
> > > > > new
> > > > > > > > > event? Yakov's issue was that you propagated
private
> > interface
> > > to
> > > > > > > public
> > > > > > > > > API, which is bad of course. Come up with a clean
design
> and
> > it
> > > > > will
> > > > > > be
> > > > > > > > > accepted.
> > > > > > > > >
> > > > > > > > > My problem with TransactionValidator is that
it only
> solves a
> > > > small
> > > > > > > > problem
> > > > > > > > > for transactions. If we do that, then we will
have to add
> > cache
> > > > > > > > validators,
> > > > > > > > > compute validators, etc, etc, etc. That is why
we either
> > should
> > > > use
> > > > > > the
> > > > > > > > > existing event subsystem or come up with a holistic
design
> > that
> > > > > will
> > > > > > > work
> > > > > > > > > across the whole project.
> > > > > > > > >
> > > > > > > > > D.
> > > > > > > > >
> > > > > > > > > On Thu, May 24, 2018 at 1:38 AM, Anton Vinogradov
<
> > > av@apache.org
> > > > >
> > > > > > > wrote:
> > > > > > > > >
> > > > > > > > > > Dmitriy,
> > > > > > > > > >
> > > > > > > > > > Yakov is against the solution based on event
sub-system
> > > > > > > > > > >> I think that we should think about
some other solution
> > > > instead
> > > > > > of
> > > > > > > > > > altering
> > > > > > > > > > >> event sub-system.
> > > > > > > > > >
> > > > > > > > > > Also, I checked is there any chances to
fix all the
> issues
> > > > found
> > > > > by
> > > > > > > > Yakov
> > > > > > > > > > and see that solution becomes overcomplicated
in that
> case.
> > > > > > > > > > That's why I'm proposing this lightweight
solution.
> > > > > > > > > >
> > > > > > > > > > As for me it's a good idea to have such
validator since
> > > that's
> > > > a
> > > > > > > common
> > > > > > > > > > problem at huge deployments when more than
one team have
> > > access
> > > > > to
> > > > > > > > Ignite
> > > > > > > > > > cluster and there is no other way to setup
tx cretion
> > rules.
> > > > > > > > > >
> > > > > > > > > > Yakov,
> > > > > > > > > >
> > > > > > > > > > Could you please share your thoughts on
that?
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > чт, 24 мая 2018 г. в 8:58, Dmitriy
Setrakyan <
> > > > > > dsetrakyan@apache.org
> > > > > > > >:
> > > > > > > > > >
> > > > > > > > > > > On Wed, May 23, 2018 at 4:08 AM, Anton
Vinogradov <
> > > > > av@apache.org
> > > > > > >
> > > > > > > > > wrote:
> > > > > > > > > > >
> > > > > > > > > > > > Dmitriy, Yakov
> > > > > > > > > > > >
> > > > > > > > > > > > Are there any objections to updated
design taking
> into
> > > > > account
> > > > > > > the
> > > > > > > > > > > comments
> > > > > > > > > > > > I provided?
> > > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > Anton, I do not like an additional
validator. I think
> you
> > > can
> > > > > > > > > accomplish
> > > > > > > > > > > the same with a transaction event.
You just need to
> > design
> > > it
> > > > > > more
> > > > > > > > > > cleanly,
> > > > > > > > > > > incorporating the feedback from Yakov.
> > > > > > > > > > >
> > > > > > > > > >
> > > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
>

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