Re: AW: AW: Fw: GPL / LGPL

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?

What is your isolation level?

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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> >
> > > guy.
> > >
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> > > > _______________________________________________
> > > > Ozone-users mailing list
> > > > [email protected]
> > > > https://lists.sourceforge.net/lists/listinfo/ozone-users
> > >
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> > > _______________________________________________
> > > Ozone-users mailing list
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> > >
> > >
> > >
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