RE: Syncing a file across 3 systems

[Chris Bipes <chris.bipes@xxxxxxxxxxxxxxx>]

Can all three system write/update the file?  Is there one master file and
two remote files that are read only?  What is the application like?

We mirror several files for our authorization system by sending transactions
thru data queues.  Each system writes to a local DQ and remote system pull
using DDM queues pointing to the approximate DQ on the sending system.  All
DQ entries follow the same structure. The first part is the library, file,
rcdfmt, source job(26 bytes), and source program.  Following is the data
structure specified in the first three parms.  We use external DS to format
the data in the queues.  By using bases DS you set pointer to the variable
you read the data into which is defined at the max size of the DQ.

Now our application has few updates to records, mosting writing
transactions.  We have audits that use DDM to compare files and ensure data
is not lost.  We also use a combination of system/sequence number to make
sure we do not loose transactions.  We really do not update transactions, we
create new ones that flag the origional as deleted.  Posting those new
transaction actually update the old ones locally so we do not have to mirror
the old transactions.  Mirroring rarely laggs more than a second behind.
Communicaition failures does not stop transaction processing, just delays
mirroring, which can cause other problems, but that is an evaluated risk
that we accept.

Good Luck and contact me if you want more detailed info.

Christopher K. Bipes          mailto:ChrisB@Cross-Check.com
Operations & Network Mgr  mailto:Chris_Bipes@Yahoo.com
CrossCheck, Inc.                http://www.cross-check.com
6119 State Farm Drive         Phone: 707 586-0551 x 1102
Rohnert Park CA  94928      Fax: 707 586-1884



-----Original Message-----
From: Wills, Mike N. (TC) [mailto:MNWills@taylorcorp.com]
Sent: Tuesday, April 09, 2002 2:58 PM
To: Midrange - Midrange-L (E-mail)
Subject: Syncing a file across 3 systems


We have a file (with 2 logicals) that is the same on three different
systems, and so we have to maintain three separate files. How can we
synchronize this file across 3 systems? And we want it to be reliable but
would highly prefer to not spend money on a program. DDM doesn't seem to be
reliable across all the systems. Could RSF be used somehow?