Subject RE: [ib-support] Re: Replication ATT PETE B.
Author Pete Bray

this is pretty much the way my app works. it is used as a tech support
communication tracker written with Delphi 4 using FIB connectivity
components. the head office has a lan with the users attaching to their
local master copy of the database. the outworkers work in 2 different ways
depending upon the available connection bandwidth.

ADSL connections either connect direct to the head office server using ssh
(with data compression which is essential to cope with the varchar padding),
or synchronize with the master database in the same way as the dial-up
connection users. direct connections like this work ok so long as the amount
of live data displayed is kept to a minimum (i have a multi page datagrid
with 5 grids each with about 50 records displayed). I used to broadcast any
changes to each client using interbase/fb events so that everybodies screen
was kept up to date but have now put a manual update button on for the
remote workers.

Dialup users (with ISDN and 56k modems). these users sync to the master
database as the app starts. I use Indy components for remote connectivity, a
dialup component to provide control of the connection. the application
attaches to a local copy of the database and also to the remote master copy.
I use stored procedures to pump records based on the modification timestamp.
Data is mostly transferred in both directions (the master holds extra data
such as the remote worker sync history etc). After the remote worker has
finished using the app if any records have been modified or added the app
automatically synchronizes again. A typical session requires about 1 minute
to sync so long as the app is run a couple of times per day (go away for a
weeks holiday and it takes a bit longer!).

One of the adsl users uses the sync method (rather than live connection) but
this requires a 2nd machine to run the ssh client software.

i'm not familiar with the technology but i guess you could achieve much of
the above using an adsl router which had VNC.

email me privately if you want more info (to save the ib-support bandwidth).

Kind regards,

> From: Michael Vilhelmsen [mailto:Michael.Vilhelmsen@...]
> I would like to have a DB running at the main site, where clients
> connects via LAN.
> And on my remote sites, I would like to have a "copy" of my DB.
> Then at some either scheduled time, randomly, at data change etc. I
> would like the replications to go on.
> Would this be good with a 56K modem line ?
> Would this be good with an ISDN Line ?
> Or would this be good with an ADSL line ?
> I would have to do replication both ways on some data, and 1 way on
> others.
> Is this posible ?
> At your particullar site, what specific product do you use (DB,
> Programs (your own or bought ones), replication programs, etc).
> Hope you can give me more information on this subject.