[tarantool-patches] Re: [PATCH 02/10] ddl: synchronize user cache with actual data state

[Konstantin Osipov]

* Vladimir Davydov <vdavydov.dev at gmail.com> [19/07/03 23:05]:
> > > See also commit 22bedebe715c ("ddl: synchronize privileges cache with
> > > actual data state").
> > 
> > Here's a problem with replacing before commit:
> > 
> > Imagine you have a yielding transaction, which is in progress.
> > 
> > You replace state in the metadata cache, it doesn't matter what
> > cache - user, view, space, trigger, or whatever.
> > 
> > Then you yield on DDL.
> 
> If we yield from a DDL transaction, we must invoke on_rollback triggers
> immediately. I don't see any problem with that. If we don't do that now,
> I'll change that soon enough.

any transaction yields on WAL write. With synchronous replication
it will also involve a network round trip to get a quorum
responses - so a failure is more likely to happen. And then we
have a cascading rollback.


-- 
Konstantin Osipov, Moscow, Russia