multiuser dbc extremely slow when accessed from different machines

From: broekhuis (info_at_bah.nl)
Date: 08/13/04 

Date: Fri, 13 Aug 2004 12:23:47 +0200

Hi,

In a testproject I have created a simple form with a procedure doing a
lock->replace>unlock operation on 10000 records.
The database is a .DBC with one table (.DBF). The .DBC is opened SHARED and
the tables are not used exclusive.
All files are stored on a Windows 2003 fileserver. In the config.fpw (also
stored on the fileserver) the following values are stored:

TMPFILES=c:\winvis
EDITWORK=c:\winvis
SORTWORK=c:\winvis
PROGWORK=c:\winvis

If the test is run on machine A the duration is average 5 secs. With the
same program started for a second time, and a third, etc., on this machine
the duration increases only slightly.
On machine B the average is 10 secs, also with multiple instances of the
program on this machine running. So far no problem.

My problem arises when both machine A and machine B use the same program.
The duration then jumps to approx. 300 secs (!) on both machines.
When both machines run a copy of the program (machine A uses proj1.exe and
machine B uses proj2.exe) makes no difference. Both machines A and B use
Windows XP Pro.

How come that running multiple instances of a program on a single machine
works full speed and using the same program on 2 different machines makes
the process extremely slow?

Regards,

Gerrit