> From: jop@...
> To: buzzheavyyear@...
> Subject: Re: escada and jgcs
> Date: Fri, 21 Sep 2007 16:11:05 +0100
> CC: community@...; nunomrc@...
>
> On Friday 21 September 2007, buzz lightyear wrote:
> > Thanks for the reference to the paper - when using jxta I'm having to take
> > into account node failure and clients are generally aware of which nodes
> > have the database - jxta is pretty good at discovery. This idea is to
> > ensure that clients connect to the 'best' connection at the time an
> > operation is invoked. The 'load balancing' is effectively taking place on
> > the client side.
>
> I understand. You should definitely take a look at the paper and think about
> the best solution for you: Enforcing some client affinity or using ESCADA in
> the proposed safe mode, which does however have an impact in read only
> transactions.
>
> > The license is an issue do to the fact that customers may construct
> > standalone applications using my libraries, your libraries and all the
> > other libraries which they might pass onto their clients. Some customers
> > may not not want to make public the source of their application. Other
> > customers may be overlook the gpl issue, distribute an application without
> > source and be unaware that they are contravening escadas license terms, and
> > as a consequence be liable. All of the libraries I'm using, including my
> > own (once they are ready), hibernate, jboss, jxta, derby etc have at worst
> > the lgpl license, and at best the apache license.
> >
> > I dearly hope we can resolve this licensing issue.
>
> IANAL, but the client application cannot be considered a derived work from
> ESCADA and thus is exempt from any licensing restrictions imposed by ESCADA.
> Let me try to explain this.
>
> Actually, this is a _major_advantage_ of the GORDA approach: replication is
> implemented by intercepting requests within the DBMS and not within the
> client application. This allows the client application (ditto JBoss,
> hibernate) to link to the original unmodified JDBC driver. No linking to
> ESCADA code is done. Besides technically interesting this should also solve
> any licensing issues.
>
> Licensing issues might arise only when linking ESCADA to the DBMS, since the
> resulting replicated DBMS is a derived work from both ESCADA and the DBMS.
> This is why we chose GPLv3, which unlike GPLv2 is compatible with Apache 2.0
> license, hence with Derby or Sequoia. There are also no problems when linking
> GPLv3 with modified-BSD licenses, hence with PostgreSQL.
>
> Moreover, like Apache License 2.0, GPLv3 should also be safer when
> redistributing code for money regarding possible patent claims.
>
> I hope this clears the licensing issue,
>
> --
> Jose Orlando Pereira