Re: AW: AW: Fw: GPL / LGPL

Hi Christian,
 
Monday 27 June 2005 15.34 skrev Christian Merenda:
> Hello Per,
>
> thanks a lot for your answers!
>
> Ok, your objects reside on the server side. But what about the isolation
> level? 

> What about concurrent access to these server-side objects? Do you 
> have server-side replicas in order to realize optimistic locking strategies
> or do you work with an pessimistic approach which simply denies concurrent
> changes until the object is released by the first transaction?

Pessimistic locking is used.

>
> What is your isolation level?

Not sure about non-repeatable and serailizable but definitely not allowing 
dirty reads. Maybe Leo, Wieslaw or Falko could share some light on this?

Best regards,
Per

>
> Thanks in advance,
> Christian
>
> > Hi Christian,
> >
> > Wednesday 22 June 2005 18.27 skrev Christian Merenda:
> > > Hello Per and all the others out there,
> > >
> > > > We are 9 committers of which three are currently active
> > > > on a regular basis (myself, Leo and Wieslaw).
> > > > In addition there are patches sent in from other developers.
> > >
> > > How many time do you - nine/three committers - spend in a week for the
> > > Ozone database project at an average? How frequently do these patches
> > > arrive out of the community? They send them via e-mail, am I right?
> >
> > I have no idea how long time spend on Ozone. I usually spend a couple of
> > hours per weeks but them sometimes when i can find some time and know
> > what do to it might be 40-60 hours per week. Falko did basically nothing
> > but coded on Ozone back in the days for a whole year...
> >
> > Patches are not wery common to be honest. Maybe one per month or less.
> >
> > > What about your transaction engine? What kind of isolation level do you
> > > support (read uncommitted, read committed, repeatable read,
> > > serializable)?
> > >
> > > What about client-server interaction? Do the persistent objects reside
> > > on the server side or do you have some kind of client-side replicas?
> >
> > All Ozone objects reside on the server side, no client-side replica. In
> > this regard Ozone is just like a J2EE type application server (though
> > simpler and much cleaner to use IMHO).
> >
> > Best regards,
> > Per
> >
> > > Best regards,
> > > Christian
> > >
> > > -----Ursprüngliche Nachricht-----
> > > Von: [email protected]
> > > [mailto:[email protected]] Im Auftrag von Per
> > > Nyfelt
> > > Gesendet: Mittwoch, 15. Juni 2005 11:31
> > > An: [email protected]
> > > Cc: Christian Merenda
> > > Betreff: Re: AW: [Ozone-users] Fw: GPL / LGPL
> > >
> > > Wednesday 15 June 2005 10.42 skrev Christian Merenda:
> > > > Thanks for your answers, Per and Kai! Now, the Ozone licensing is
> > > > absolutely clear! Under these circumstances Ozone is definitely an
> > > > option for us - we will think about it. :)
> > >
> > > Great!
> > >
> > > > Regarding a potentially integration effort, I've got two questions:
> > > >
> > > > 1. How many developers are involved in the Ozone project? Probably
> > >
> > > there
> > >
> > > > are only a few core developers...? Is that right? How many? Who? Have
> > > > other people contributed little code to the Ozone database
> > >
> > > additionally?
> > >
> > > > How many are involved alltogether?
> > >
> > > We are 9 committers of which three are currently active on a regular
> > > basis
> > > (myself, Leo and Wieslaw). In addition there are patches sent in from
> > > other
> > > developers. Once such a developers shows signs of commitment over time
> > > we
> > > uncourage him/her to become committer with direct access to the CVS
> > > repository.
> > >
> > > > 2. How does your mapping between objects and disk space work? I know,
> > > > that you use some kind of serialization mechanism.
> > >
> > > Yes, we use the built-in Serialization mechanism as the base for Object
> > > persistance in Ozone.
> > >
> > > > Nevertheless a
> > > > database system should know about pages ... As Ozone has no query
> > > > facility do you optimize the object storage task in a way that nearby
> > > > objects are stored on the same page so that navigation in an object
> > > > graph is optmized?
> > >
> > > Yes, related objects are stored in clusters. The current default
> > > back-end
> > > storage engine (WizardStore) has been the storage of choice for the
> > > last 5
> > > years (ClassicStore, the original storage engine is currently broken).
> > > There
> > > is also a variation of WizardStore called MagicStore with some
> > > performance
> > > improvements compared to WizardStore. Leo is working on a new back-end
> > > (GammaStore) which will further improve scalability and performance. We
> > > hope
> > > to have GammaStore ready to ship with 1.3. See ozone-dev mailing list
> > > archive
> > > for more details on this.
> > >
> > > Best regards,
> > > Per
> > >
> > > > -----Ursprüngliche Nachricht-----
> > > > Von: [email protected]
> > > > [mailto:[email protected]] Im Auftrag von Per
> > > > Nyfelt
> > > > Gesendet: Dienstag, 14. Juni 2005 12:26
> > > > An: [email protected]
> > > > Cc: Kai Schutte; [email protected]
> > > > Betreff: Re: [Ozone-users] Fw: GPL / LGPL
> > > >
> > > > These are good points. I think that it should be OK for anyone,
> > > > commercial or
> > > > not to create Ozone based applications without forcing them to comply
> > >
> > > to
> > >
> > > > any
> > > > type of licensing restrictions. This is how i understand LGPL and
> > > > this is why
> > > > the public api (the one that the client i.e. the Ozone based app is
> > > > using) is
> > > > LGPL. However if modifications to the actual Ozone code is made these
> > > > modifications should be given back to the community. Also if someone
> > > > takes
> > > > the Ozone codebase and decides to fork this fork should be open
> > >
> > > source.
> > >
> > > > This
> > > > is why the Ozone core is GPL. This means in short
> > > >
> > > > 1. It is OK to ship commercial apps based on Ozone without having to
> > > > open
> > > > source the app. In fact I would encourage more commercial Ozone Based
> > > > apps!
> > > >
> > > > 2. If changes to Ozone is needed for the commercial application those
> > > > changes
> > > > need to be either GPL or LGPL depending on if the change is in the
> > > > public API
> > > > or in the core. The best way for the commercial vendor to make sure
> > > > improvements gets incorporated into the mainstream code is to get
> > > > involved in
> > > > the development of Ozone. We are in the process of figuring out a way
> > >
> > > to
> > >
> > > > receive donations (through the SourceForge donation system). This
> > >
> > > would
> > >
> > > > be
> > > > another way to give back to the developers of Ozone and let them
> > >
> > > benefit
> > >
> > > > from
> > > > some of the profit generated by a successfull commercial, Ozone-based
> > > > app.
> > > >
> > > > Coming back to the questions posed by Christian Merenda:
> > > > >Which license corresponds to which part of the database system?
> > > >
> > > > As explained above. Clients interact with LGPL code. The public
> > > > (LGPL) api
> > > > interacts with the Core, which is GPL.
> > > >
> > > > > >If you_re restraining the core to the GPL, ozone would be no
> > > > > > option
> > > >
> > > > for
> > > >
> > > > > >everybody who plans to distribute a commercial and proprietary
> > > > > >application.
> > > >
> > > > Sure it would. As long as you do not modify the Ozone code and only
> > > > interact
> > > > with the public api you're perfectly fine.
> > > >
> > > > > > We´re strongly contributed to Open Source and we´re planning to
> > >
> > > give
> > >
> > > > > > our work back to the Open Source Community under the GPL. So it´s
> > > > > > absolutely free to use in the Open Source Environment.
> > >
> > > Additionally
> > >
> > > > we
> > > >
> > > > > > will offer a proprietary, commercial license for the rest of the
> > > > > > industrie. Can we do this with Ozone in the back-end? Do you
> > > > > > offer
> > > >
> > > > the
> > > >
> > > > > > product under the LGPL?
> > > >
> > > > Yes you're code talks to the Ozone API which is LGPL. Thus linking to
> > >
> > > an
> > >
> > > > Ozone
> > > > back end poses no restrictions on how you license your code (be it
> > >
> > > GPL,
> > >
> > > > APL,
> > > > commercial or whatever)
> > > >
> > > > > > Additionally it could be interesting for you to tightly integrate
> > > > > > Ozone with our product. If we work together, we can squeeze out
> > >
> > > the
> > >
> > > > > > maximum amount of performance of an ODBMS with the highest level
> > >
> > > of
> > >
> > > > > > abstraction ever seen on the market. What do you think about
> > > > > > this?
> > > >
> > > > Sounds interesting. Please elaborate!
> > > >
> > > > Best regards,
> > > > Per
> > > >
> > > > Monday 13 June 2005 12.19 skrev Kai Schutte:
> > > > > I recently asked MySQL directly about a similar question. The MySQL
> > > > > server itself is GPL, and the server also can be compiled as a
> > >
> > > library
> > >
> > > > > that can be directly linked with other code. The 'connectors', ie
> > >
> > > the
> > >
> > > > > drivers which manage a connection to MySQL are also GPL, which
> > > > > means that any application that you write that either links with
> > > > > the
> > >
> > > library
> > >
> > > > > version of the server or any of the drivers they provide must also
> > >
> > > be
> > >
> > > > > GPL, *unless* you purchase their commercial license. This also
> > > > > means that if you write your own connector which handles a network
> > > >
> > > > connection
> > > >
> > > > > to the MySQL server, you do not need your code to be GPL nor
> > >
> > > purchase
> > >
> > > > a
> > > >
> > > > > commercial license, as your code doesn't link with anything GPL.
> > > > >
> > > > > The hitch with GPL is that anything that links to it must also be
> > >
> > > GPL.
> > >
> > > > > It is a violation of the license to link and LGPL code with GPL
> > >
> > > code.
> > >
> > > > > (Of course, if you're the author, you're allowed to do that,
> > > > > because you're the only person who can sue yourself). Linking Bob's
> > > >
> > > > proprietary
> > > >
> > > > > code with Alice's LGPL code which links with Alice's GPL code is a
> > > >
> > > > clear
> > > >
> > > > > violation. The only way you can use a GPL database server with
> > > > > proprietary code is through a network connection.
> > > > >
> > > > > Hence, if the product that Christian Meranda is working on would
> > > >
> > > > require
> > > >
> > > > > linking to GPL code (within the same application space) and this
> > >
> > > code
> > >
> > > > is
> > > >
> > > > > to be redistributed under the GPL, all is good. But, if they want
> > > > > to resell a commercial license for their clients to use their
> > > > > product
> > > >
> > > > which
> > > >
> > > > > includes Ozone GPL code, that's obviously a violation, because
> > > >
> > > > Christian
> > > >
> > > > > Merenda is distributing his work under a different license which
> > >
> > > links
> > >
> > > > > to GPL code and the GPL doesn't allow that. The only solution here
> > >
> > > is
> > >
> > > > if
> > > >
> > > > > Ozone itself would be distributed under a different license.
> > > > >
> > > > > In my opinion, if Christian Merenda wants to sell his work which
> > > >
> > > > relies
> > > >
> > > > > on Ozone being in the same application space, aren't Ozone
> > >
> > > developpers
> > >
> > > > > entitled to some share of the funds? (ie, make a commercial license
> > > > > scheme for Ozone).
> > > > >
> > > > > -kai
> > > > >
> > > > > (btw, I'm not an Ozone dev, I'm just thinking out loud :) )
> > > > >
> > > > > Gerd Mueller wrote:
> > > > > >Begin forwarded message:
> > > > > >
> > > > > >Date: Sun, 12 Jun 2005 17:25:14 +0200
> > > > > >From: "Christian Merenda" <[email protected]>
> > > > > >To: <[email protected]>
> > > > > >Subject: GPL / LGPL
> > > > > >
> > > > > >
> > > > > >Dear sir / madam,
> > > > > >
> > > > > >on your website  <http://www.ozone-db.org/> www.ozone-db.org you
> > >
> > > have
> > >
> > > > to
> > > >
> > > > > >licenses _Ozone Library License_ and _Ozone Core License_. The
> > >
> > > first
> > >
> > > > is
> > > >
> > > > > >essentially based on the LGPL, the second one on the GPL.
> > > > > >
> > > > > >So I do not understand which license is the right one or better to
> > > >
> > > > say:
> > > > > >Which license corresponds to which part of the database system?
> > > > > >
> > > > > >If you_re restraining the core to the GPL, ozone would be no
> > > > > > option
> > > >
> > > > for
> > > >
> > > > > >everybody who plans to distribute a commercial and proprietary
> > > > > >application.
> > > > > >
> > > > > >In our special case, we have developed a very smart
> > > > > > object-oriented database metamodel and API, which could be
> > > > > > implemented on top of different back-ends. We_ve done already for
> > > > > > JBoss and Ozone is
> > > >
> > > > another
> > > >
> > > > > >option for us. As our model-driven architecture approach is
> > >
> > > extremely
> > >
> > > > > >powerful and complemented with a best-of-class IDE it could give
> > > >
> > > > Ozone a
> > > >
> > > > > >boost in widespread application.
> > > > > >
> > > > > >We_re strongly contributed to Open Source and we_re planning to
> > >
> > > give
> > >
> > > > our
> > > >
> > > > > >work back to the Open Source Community under the GPL. So it_s
> > > >
> > > > absolutely
> > > >
> > > > > >free to use in the Open Source Environment. Additionally we will
> > > >
> > > > offer a
> > > >
> > > > > >proprietary, commercial license for the rest of the industrie. Can
> > >
> > > we
> > >
> > > > do
> > > >
> > > > > >this with Ozone in the back-end? Do you offer the product under
> > > > > > the LGPL?
> > > > > >
> > > > > >Additionally it could be interesting for you to tightly integrate
> > > >
> > > > Ozone
> > > >
> > > > > >with our product. If we work together, we can squeeze out the
> > >
> > > maximum
> > >
> > > > > >amount of performance of an ODBMS with the highest level of
> > > >
> > > > abstraction
> > > >
> > > > > >ever seen on the market. What do you think about this?
> > > > > >
> > > > > >Best regards,
> > > > > >Christian Merenda
> > > > > >
> > > > > >----------------------------
> > > > > >Christian Merenda
> > > > > >Franz-Joseph-Str. 7
> > > > > >80801 München
> > > > > >
> > > > > >Tel.: 0 89/82 90 97-17
> > > > > >Fax: 0 89/82 90 97-18
> > > > > >E-Mail:  <mailto:[email protected]> [email protected]
> > > > > >Web:  <http://www.merenda.de> www.merenda.de
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >----------------------------------------------------------------
> > > > > >Gerd Mueller                                    [email protected]
> > > > > >SMB GmbH                                  http://www.smb-tec.com
> > > > > >
> > > > > >
> > > > > >!DSPAM:42ad353e230183574914120!
> > >
> > > -----------------------------------------------------------------------
> > >-
> > >
> > > > > > Dear sir / madam,
> > > > > >
> > > > > > on your website www.ozone-db.org <http://www.ozone-db.org/> you
> > >
> > > have
> > >
> > > > > > to licenses „Ozone Library License” and „Ozone Core License“. The
> > > > > > first is essentially based on the LGPL, the second one on the
> > > > > > GPL.
> > > > > >
> > > > > > So I do not understand which license is the right one or better
> > > > > > to say: Which license corresponds to which part of the database
> > >
> > > system?
> > >
> > > > > > If you’re restraining the core to the GPL, ozone would be no
> > >
> > > option
> > >
> > > > > > for everybody who plans to distribute a commercial and
> > > > > > proprietary application.
> > > > > >
> > > > > > In our special case, we have developed a very smart
> > >
> > > object-oriented
> > >
> > > > > > database metamodel and API, which could be implemented on top of
> > > > > > different back-ends. We´ve done already for JBoss and Ozone is
> > > >
> > > > another
> > > >
> > > > > > option for us. As our model-driven architecture approach is
> > > >
> > > > extremely
> > > >
> > > > > > powerful and complemented with a best-of-class IDE it could give
> > > >
> > > > Ozone
> > > >
> > > > > > a boost in widespread application.
> > > > > >
> > > > > > We´re strongly contributed to Open Source and we´re planning to
> > >
> > > give
> > >
> > > > > > our work back to the Open Source Community under the GPL. So it´s
> > > > > > absolutely free to use in the Open Source Environment.
> > >
> > > Additionally
> > >
> > > > we
> > > >
> > > > > > will offer a proprietary, commercial license for the rest of the
> > > > > > industrie. Can we do this with Ozone in the back-end? Do you
> > > > > > offer
> > > >
> > > > the
> > > >
> > > > > > product under the LGPL?
> > > > > >
> > > > > > Additionally it could be interesting for you to tightly integrate
> > > > > > Ozone with our product. If we work together, we can squeeze out
> > >
> > > the
> > >
> > > > > > maximum amount of performance of an ODBMS with the highest level
> > >
> > > of
> > >
> > > > > > abstraction ever seen on the market. What do you think about
> > > > > > this?
> > > > > >
> > > > > > Best regards,
> > > > > >
> > > > > > Christian Merenda
> > > > > >
> > > > > > ----------------------------
> > > > > >
> > > > > > Christian Merenda
> > > > > >
> > > > > > Franz-Joseph-Str. 7
> > > > > >
> > > > > > 80801 München
> > > > > >
> > > > > > Tel.: 0 89/82 90 97-17
> > > > > >
> > > > > > Fax: 0 89/82 90 97-18
> > > > > >
> > > > > > E-Mail: [email protected] <mailto:[email protected]>
> > > > > >
> > > > > > Web: www.merenda.de <http://www.merenda.de>
> > > > >
> > > > > -------------------------------------------------------
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> > >
> > > you
> > >
> > > > > shotput a projector? How fast can you ride your desk chair down the
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> > > > > luge track? If you want to score the big prize, get to know the
> > >
> > > little
> > >
> > > > guy.
> > > >
> > > > > Play to win an NEC 61" plasma display: http://www.necitguy.com/?r
> > > > > _______________________________________________
> > > > > Ozone-users mailing list
> > > > > [email protected]
> > > > > https://lists.sourceforge.net/lists/listinfo/ozone-users
> > > >
> > > > -------------------------------------------------------
> > > > This SF.Net email is sponsored by: NEC IT Guy Games.  How far can you
> > > > shotput
> > > > a projector? How fast can you ride your desk chair down the office
> > >
> > > luge
> > >
> > > > track?
> > > > If you want to score the big prize, get to know the little guy.
> > > > Play to win an NEC 61" plasma display: http://www.necitguy.com/?r
> > > > _______________________________________________
> > > > Ozone-users mailing list
> > > > [email protected]
> > > > https://lists.sourceforge.net/lists/listinfo/ozone-users
> > > >
> > > >
> > > >
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