Alex, I think we should put consecutive checkpoints to stack thus your
example should be illegal and should result to exception. And we will throw
exception on rollback to CP if CP is not defined.
--Yakov
2016-11-07 14:23 GMT+03:00 Alexey Goncharuk <alexey.goncha...@gmail.com>:
> We also should define savepoint behavior and API rules for each of the
> transaction concurrency and isolation types.
>
> * Should rollbackToSavepoint() always release locks or clear saved
> optimistic versions?
> * Are forward-rollbacks allowed, e.g.
>
> try (Transaction tx = ignite.transactions().txStart()) {
> c.put(1, 1);
>
> tx.savepoint("sp1");
>
> c.put(2, 2);
>
> tx.savepoint("sp2")
>
> c.put(3, 3);
>
> tx.rollbackToSavepoint("sp1");
>
> c.put(4, 4);
>
> tx.rollbackToSavepoint("sp2"); // Is this allowed?
>
> tx.commit();
> }
>
>
> 2016-11-07 13:47 GMT+03:00 Sergey Kozlov <skoz...@gridgain.com>:
>
> > Hi, Yakov
> >
> > I suppose it's very very handy feature.
> > My two cents are following:
> > - number of savepoints may be more than one per transaction
> > - what's about RELEASE SAVEPOINT statement?
> >
> >
> > On Mon, Nov 7, 2016 at 11:24 AM, Yakov Zhdanov <yzhda...@apache.org>
> > wrote:
> >
> > > Guys,
> > >
> > > Let's think of implementing savepoints for Ignite transactions. For me,
> > > this is not too hard to do.
> > >
> > > Having "savepoints" seems to be pretty handy. Please consider the
> > following
> > > snippet.
> > >
> > > ignite.transactions.;
> > > INSERT INTO table1 VALUES (1);
> > > SAVEPOINT my_savepoint;
> > > INSERT INTO table1 VALUES (2);
> > > ROLLBACK TO SAVEPOINT my_savepoint;
> > > INSERT INTO table1 VALUES (3);
> > > COMMIT;
> > >
> > > Which should result in values 1 and 3 inserted to table1.
> > >
> > > In Ignite, I think, it would be like the following (preserving the
> same
> > > behavior as above).
> > >
> > > Ignite ignite = ....;
> > > IgniteCache<Integer, Integer> c = ....;
> > >
> > > try (Transaction tx = ignite.transactions().txStart()) {
> > > c.put(1, 1);
> > >
> > > tx.savepoint("mysavepoint");
> > >
> > > c.put(2, 2);
> > >
> > > tx.rollbackToSavepoint("mysavepoint");
> > >
> > > c.put(3, 3);
> > >
> > > tx.commit();
> > > }
> > >
> > > As far as implementation complexity I would give 2 weeks ballpark.
> > >
> > > 5 days - API design and implementation for different types of
> > transactions
> > > - savepoint implementation for local transaction objects
> > > - rollback implementation for different types of transactions - drain
> > local
> > > tx buffers, release remote locks for pessimistic transactions, etc.
> > >
> > > 5 days - testing, benchmarking, fixing issues.
> > >
> > > Please leave your comments here. I will file a ticket after we discuss
> > this
> > > and put our summary to it.
> > >
> > > Thanks!
> > >
> > > --Yakov
> > >
> >
> >
> >
> > --
> > Sergey Kozlov
> > GridGain Systems
> > www.gridgain.com
> >
>
