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Re: smtp-policy.db and other bdb's via NFS

On Thu, Mar 18, 2004 at 05:48:36PM -0300, Mariano Absatz wrote:
> Hi,
> I think I asked this before here and the only answer came from Eugene, 
> telling me to use cfengine.
> However, I have a new case where cfengine will not be as effective...
> Has anyone experience using smtp-policy.db, userdb.db, routes.db and the 
> like in a fast NFS mount?
> The databases would NEVER be modified from the mail servers, but from a 
> central server (that has them also NFS mounted), and most of them will 
> actually be dinamically modified (not via 'newdb').

  Db-file recompile method (e.g. what  "zmailer newdb" does)  should be 
  successfully autosensed over NFS, and handled in consistent manner.

  What will NOT be successfull is concurrent-data-store access in
  Sleepycat DB.  Shared-memory segments don't fly over NFS very

  What _might_ work is GNU GDBM shared writer access with its locking
  schemes.  Things I faintly recall about it might allow successfull
  shared access over NFS.  (fcntl locking, no shared memory things.)
  Reading gdbm's documents:
    Readers and writers can not open the `gdbm' database at the same time.
  Oh, uh..   No can do.

  What COULD work (even handsomely) is RPC mode of Sleepycat DB.
  However it will require additional code in the router system ..
  .. and isn't supportable in smtpserver without considerable
  modifying of "PARAM policydb" processing.    Hmm..  introducing
  new dbtype, perhaps "sleepyrpc",  and 'file' parameter would then
  point to configuration file with necessary parameters ?
  The   lib/sleepycatdb.c  function collection isn't quite generic
  enough to be used at present anywhere, but inside the router.

  I was entertaining an idea of replicating sleepycat db thru
  its builtin replication support ("some" user code required!)
  but that is rather over-complicated thing..

> --
> Mariano Absatz
> El Baby
/Matti Aarnio	<mea@nic.funet.fi>
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