Conference ilbbak::ibi_focus

539.0. "How does the FOCUS DBMS run in a cluster ?" by UTRUST::HERWIJNEN (Errare Humanum Est) Thu Nov 26 1992 11:13

    A customer of mine is purchasing a FOCUS-based application which he
    would like to use in a cluster-environment. Now I know that Oracle and
    Ingres have some nitty gritty problems in a cluster-environment and
    this customer also knows this. So he wonders whether FOCUS will work in
    the same transparant way as Rdb or that he should be aware of any nitty
    gritty details that could corrupt his database if care isn't taken.
    
    I read some previous notes about this topic, but them seem pretty much
    dated and I wonder if things have changed since then. I gather from
    these notes that there seems to be a SU-facility that is the
    database-facility for multi-user access. I understand from the previous
    notes that this facility must run on only one of the cluster-nodes and
    the others must access the database remotely via the USE-command.
    
    My question(s) is(are):
    
    - Is this the only way to make FOCUS run on multiple nodes in a
      cluster or are there (nowadays) better ways to run FOCUS in a cluster
      environment ?
    - Can an already written application easily be adapted for remote
      access ? Is this USE-command something that can be issued from
      outside the application ? (Some node-specific startup file perhaps ?)

    Thanks in advance for any answers.
    
    Jaco

Jaco,

It's been a while since I've worked with a customer using FOCUS with
its own database, but I doubt they've changed much (they seem like
many other 4GLs to be concentrating on the 4GL rather than the
database).

The FOCUS database is handled by ONE server, period, and that server
(if memory serves) is ALWAYS reached through DECNET (even on one
CPU). Furthermore, the experience of my customer is such that I
would NEVER recommend using FOCUS with its own database on a VAX.

Peter

    FOCUS with RDB is a stable solution

    Thanks, this is the sort of answer I expected. I guess developments
    around the FOCUS DBMS have pretty much stablized and not much news is
    to be expected.