Subject Re: Clustering
Author Bert_Herngreen
Thank you for this information, it's even harder than I thought :-)
I'll take a look at sourceforge for OpenDLM.


--- In, "Ann W. Harrison"
<aharrison@i...> wrote:
> At 09:46 AM 11/14/2004, Bert_Herngreen wrote:
> >I'm trying to find out how I can create a cluster for testing
> >purposes. Until now I didn't find information for firebird on this.
> There is no information to find. InterBase, the precursor to
> ran - probably still runs - on VAX Clusters. Other than that,
there is
> no cluster support for Firebird.
> >I read about openmosix and doubt if this can
> >be used to let the 2 computers in the cluster talk to each other
> >share load.
> It won't. Firebird runs in two modes: classic and Superserver.
> In Superserver and embedded which uses the same architecture, a
> process handles all data activity. Swapping that process back and
> forth between processors will achieve no parallelism and incur the
> cost of the swap. In short, a big lose.
> In Classic mode, many separate processes access the database
> simultaneously. That is the mode that worked on VAX clusters.
> However the processes must coordinate their read/write activities.
> VAX clusters include a distributed lock manager which provides that
> coordination. Firebird uses a shared memory lock manager, similar
> in design to the VAX lock manager. It works on SMP because the
> processors share memory. Without shared memory, it won't work.
> The OpenDLM project may provide a solution and should be studied.
> Regards,
> Ann