Sorry wrong link..

This is correct:

http://c-jdbc.objectweb.org/current/doc/C-JDBC_Flexible_Database_Clustering_Middleware.pdf

mvh
Jesper B. Kiær



Firebird-Architect@yahoogroups.com wrote on 03-08-2005 11:57:41:

> Hi
>
> Havening been a Notes/Domnio developer/administrator for over 10 years I

> can not expres my fondness for replication high enough.
>
> To simply a new Domino server to a cluster ...wupti ..the clustered
> databases get replicated realtime. If a clustered server goes down it
> ..the databases just gets replicated when it gets back up and everything

> is in sync.
>
> As a database administrator this is really what you ove.
>
> I love Firebird and to get some kind of simular replication features

would

> be fantastic! :-)
>
>
> Until then I advise (Java) people to take a good look at C-JDBC -
> Software Raid features for databases. I think their ideas are simply
> great.
>
>
>
>
> link : http://c-jdbc.objectweb.org/
>
> and this http://c-jdbc.objectweb.org/current/doc/C-JDBC.pdf to learn

more

> about.
>
> Very interesting reading.
>
>
> Thanks to everybody working on Firebird!
>
> It is really great to see everybody striving for making a great database

> system .. even better! :-)
>
> Best Regards
> Jesper B. Kiær
>
>
>
> Firebird-Architect@yahoogroups.com wrote on 02-08-2005 18:06:12:
>
> > t_j_haynes wrote:
> >
> > >Have to agree that trigger based replication is a lot more flexible -

> > >but it's arguable that this very flexibility allows far more scope
> > >for error.
> > >
> > >Setting up a shadow is really easy and it should be relatively simple

> > >to allow it to shadow to an adjacent computer over a dedicated
> > >gigabit network cable without trashing the shadow if the other
> > >machine is unavailable for a few seconds or minutes.
> > >
> > >
> > It's a lot more complicated than that. If the connection drops, there

> > has to be a resynchronization mechanism to bring the shadow back in
> > sync, meaning that state must preserved both on the shadow and primary

> > systems as well as a mechanism for the shadow machine to identify
> > itself. Keep in mind that if the the shadow machine crashed, it may

be

> > necessary to go back a repeat a sequence of pages to make sure every

one

>
> > gets copied. Clone a new copy is an alternative, but a little pricey

on

>
> > a hundred gig database.
> >
> > But it could be done, of course. But I don't see anybody jumping up

and

>
> > down to take this on, particularly since much of what shadows once did

> > is now handled better by RAID.
> >
> > There is no question, however, that disaster recovery must be one of
> > Firebird's highest priorities.
> >
> > >The nearest I have to a performance comparison is between shadow
> > >mechanism and stnadards triggers. Daabase write time to a single
> > >table rose ~30% with a shadow, and over 100% using a trigger to copy
> > >changed records. It seems to stand to reason that the raw disk block

> > >level version should be faster, but I haven't tried your idea of
> > >taking the processing to an external process, so I'll have a look.
> > >
> > >
> > There will always be a tradeoff between bandwidth and cpu. If you're
> > doing replication over a gigabit ethernet, you don't care about
> > bandwidth. If you're replicating over a modest speed line to machine

in

>
> > a bunker 40 miles aways (as one of my customers does), you do care

about

>
> > bandwidth.
> >
> > RAID is cheapest, shadows next, and replication the most expensive.

You

>
> > get what you paid for.
> >
> > >Still - guess I have to live with what's there!
> > >
> > >
> > >
> > Then you are definitely on the wrong list. The developer's list is

for

> > people who aren't content with what's there.
> >
> > --
> >
> > Jim Starkey
> > Netfrastructure, Inc.
> > 978 526-1376
> >
> >
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
>
>
> [Non-text portions of this message have been removed]
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>

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