ignite-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Dmitriy Setrakyan <dsetrak...@apache.org>
Subject Re: CacheEntry serialization failure
Date Mon, 21 Dec 2015 08:18:35 GMT
Vova,

Shouldn’t it be the other way around? Class B writes the field as “a”, and
class A writes it with a prefix (possibly the hash code of the class name).

Also, we should clearly document how the SQL queries are affected by this.
AFAIK, we should be using field aliases here, no?

D.

On Sun, Dec 20, 2015 at 10:08 AM, Vladimir Ozerov <vozerov@gridgain.com>
wrote:

> May be we can use normal field names by default and add some prefix/suffix
> if conflict is found? E.g.:
>
> class A {
>     int a; // Write as "a";
> }
>
> class B extends A {
>     int a; // Write as "B_a";
> }
>
> On Fri, Dec 18, 2015 at 10:34 PM, Valentin Kulichenko <
> valentin.kulichenko@gmail.com> wrote:
>
> > Folks,
> >
> > It seems to me that issue here is not with 3rd-party libraries. We just
> > don't properly support class hierarchy in binary format. Any class that
> > extends another class and has the field with the same name as parent has
> > will fail unless user provides custom serialization logic that will
> handle
> > it.
> >
> > What if we prepend the field name with the simple class name in this
> case?
> > Say, we have two classes:
> >
> > class A {
> >   private int id;
> > }
> >
> > class B extends A {
> >   private int id;
> > }
> >
> > In this case we will get two fields: "A.id" and "B.id". The only issue is
> > that if there are no name conflict, we should be able to resolve by both
> > names - with or without prepended type name. I.e., if A is serialized,
> you
> > can get the field value by "id" or "A.id". This is similar to how it
> works
> > if you join two SQL tables with the same column names.
> >
> > Any thoughts on whether it's doable or not?
> >
> > -Val
> >
> > On Fri, Dec 18, 2015 at 10:05 AM, Andrey Kornev <
> andrewkornev@hotmail.com>
> > wrote:
> >
> > > In this particular case, the class that fails is a non-static inner
> class
> > > that extends another non-static inner class, so they both end up having
> > the
> > > compiler-generated "this$0" field.
> > >
> > > Regards
> > > Andrey
> > >
> > > > Date: Fri, 18 Dec 2015 20:44:12 +0300
> > > > Subject: Re: CacheEntry serialization failure
> > > > From: vozerov@gridgain.com
> > > > To: dev@ignite.apache.org
> > > >
> > > > The most straightforward solution which comes to my mind - *do not
> ever
> > > use
> > > > BinaryMarshaller by default*. Always fallback to OptimizedMarshaller
> > > unless
> > > > user explicitly asked us to use binary format (e.g. through package
> > > > wildcards).
> > > >
> > > > BTW, we already do this for Externalizable and
> readObject/writeObject.
> > > >
> > > > On Fri, Dec 18, 2015 at 8:41 PM, Vladimir Ozerov <
> vozerov@gridgain.com
> > >
> > > > wrote:
> > > >
> > > > > Ah, I saw your problem with DirectedSpecifics. We need to think
> about
> > > how
> > > > > to solve it. Here is the case:
> > > > > 1) Class is Serilzable and cannot be changed;
> > > > > 2) There are several duplicated field names;
> > > > > => BinaryMarshaller cannot handle it.
> > > > >
> > > > > Any thoughts?
> > > > >
> > > > > On Fri, Dec 18, 2015 at 8:34 PM, Vladimir Ozerov <
> > vozerov@gridgain.com
> > > >
> > > > > wrote:
> > > > >
> > > > >> I fixed the problem, it was a bug actually.
> > > > >>
> > > > >> By default classes which has some custom Java logic (e.g.
> > > Externalizable,
> > > > >> or with writeObject/readObject methods) will be written using
> > > > >> OptimizedMarshaller, so similar field names is not a problem.
> > > > >> If you want to serialize such class in binary format and have
> > > duplicate
> > > > >> field names, you should provide your own BinarySerializer, which
> > will
> > > write
> > > > >> these fields with different names.
> > > > >>
> > > > >> On Fri, Dec 18, 2015 at 8:07 PM, Andrey Kornev <
> > > andrewkornev@hotmail.com>
> > > > >> wrote:
> > > > >>
> > > > >>> How am I supposed to handle this situation if the class comes
> from
> > a
> > > 3d
> > > > >>> party I can't modify?
> > > > >>>
> > > > >>> Thanks
> > > > >>> Andrey
> > > > >>>
> > > > >>> > Date: Fri, 18 Dec 2015 09:12:22 +0300
> > > > >>> > Subject: Re: CacheEntry serialization failure
> > > > >>> > From: vozerov@gridgain.com
> > > > >>> > To: dev@ignite.apache.org
> > > > >>> >
> > > > >>> > I'll take a look.
> > > > >>> >
> > > > >>> > On Fri, Dec 18, 2015 at 4:37 AM, Valentin Kulichenko
<
> > > > >>> > valentin.kulichenko@gmail.com> wrote:
> > > > >>> >
> > > > >>> > > Folks,
> > > > >>> > >
> > > > >>> > > It looks like CacheEntry implementation (i.e.,
the entry that
> > > > >>> contains
> > > > >>> > > version) can't be properly serialized with the
> > BinaryMarshaller.
> > > I
> > > > >>> created
> > > > >>> > > the test and the ticket:
> > > > >>> https://issues.apache.org/jira/browse/IGNITE-2203
> > > > >>> > >
> > > > >>> > > Can someone take a look?
> > > > >>> > >
> > > > >>> > > -Val
> > > > >>> > >
> > > > >>>
> > > > >>>
> > > > >>
> > > > >>
> > > > >
> > >
> > >
> >
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message