Journaling/replication questions

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2005-07-28
2012-12-29
  • Edwin Clubb
    Edwin Clubb
    2005-07-28

    The Admin Guide says that "Two global directories can map segments (either the same or different global variables) to the same database file".  If journaling is enabled for this database file, would all journal records be written to the same journal file, even if updates are made by processes using different global directories?

    The Admin Guide also says that "All GT.M processes accessing a replicated database must use the same Global Directory".  Is this still true?  My situation is that I have several database files being replicated and currently all M processes use the same global directory.  But I would like to set up an alternate directory for certain M processes to limit access to a subset of the existing globals.  However I still want all global updates to be replicated.  Is this possible?

    Ed

     
    • Ed,

      1) Yes. What matters is the database where the update happens not the global directory through which it happens. Therefore in your case both updates will be journaled in the same journal file.

      2) It is certainly possible. The Admin Guide is actually not true. With the advent of the REPLICATION INSTANCE file (not yet implemented in VMS), there is no need for all processes to use the same global directory (i.e. $gtmgbldir can be different). But it is necessary that all processes use the same replication instance file ($gtm_repl_instance environment variable needs to be the same for all processes). We will fix this documentation error in a future revision of the Admin Guide.

      Hope this helps.
      Narayanan.