                        Replication Engine DevPack demo
                            LPL Soft, 1995


What is the Replication Engine DevPack (RED)?
---------------------------------------------

 RED is a set of Delphi components that can convert a standard Delphi DataBase(DB)
application into a replication enabled application. Also included with RED
 - Both host and remotes updaters (with source)
 - Administration support programs

If you don't know what DB replication is, it's probable you don't need RED.
If you do, or if you need to know what it's all about, then download
RED and look it out. Better, try it out!

A discussion on replication here on Compuserve gave us the idea of posting
this demo, even if the product's not yet ready (Our help files and
documentations are not finished),so be patient with us, this product is still
in beta!

We wanted to show that a generic replication engine was possible (During the
discussion, a lot of people didn't think it was...).

What's in the Demo package?
---------------------------

We build a simple DB application and added our RED components. The Table used
(a Paradox table. It could have been a DBF table, or any BDE supported format)
contains text, numerics and Blob fields. That application is replication
enabled. The same application can function in either host or remote mode.
We also included both host and remote communication modules as well as
support programs (all of which will be included in the final product).
For obvious reasons, the only source code that's included is the DB
application source (DT2.pas). The code required by RED is clearly identified.

How do I use the demo?
----------------------

*** First, this is what you need to use it ***
1- 2 computers with modems (The demo supports up to 5 remotes). If you install
   only 1 remote, the demo can be made functional on a single computer,
   if you have 2 com ports with 2 modems, 2 phone lines and take care not to
   install the host and remote in the same directory.
2- Ms Windows 3.1 + or Win95 (Not tested on 3.0)
3- BDE support must be installed on each computer. If you have Delphi,
  look at the DataBase Application developer's guide for instructions
  on how to legally install (deploy) BDE support. Borland's C++ also
  included BDE.

*** If you have what's needed, then

1- Download REDDEMO.ZIP
2- Unzip it (using the -d option) onto a disquette
3- Install the demo on your host computer. The installation program asks you
   which (Host or remote) you are installing.
4- Configure the host, the host administration application should be running
   - Configure the comm setting item in the host INI file with
     the file/Host INI file menu item.
   - Start the Host updater. That program waits for remote users to call in
    to perform updates, so leave it running while you test RED. If it fails
    to run, make sure the comm setting is properly set up in the HSTUPD1.INI
    file. The format for the comm setting is explained in the host admin
    program's help file.
   - The help file is very crude, but explains a lot.

5- Once your host is configured, try the Host application icon. That's the
  DB application, running in host mode.

6- Install one or more remote sites (If more than one is installed, make sure
  you change the user id's to make them different for each remote).

7- Start The remote updater. Using the Options button, set the Comm setting to
  the modem's comm port and speed. If you need to change the user id, you can
  do it here also.

8- That's it! Using the DB Applications, make changes, add new records, etc.
  Try updating the remotes and see the changes being replicated on all sites.
  Adding will never cause collisions since the applications ensure the indexes
  are kept unique. But modifying can and will cause collisions if changes are
  made on both remote and host on the same record.

Note: The DB application source file has been included on the installation
disquette. It's IS NOT installed by the install program. (Name : DT2.PAS)

This demo can be distributed freely if all the files (including this one) are
kept together.

		RED technical specifications
		____________________________

DB supported		Anything that Delphi's tTable can handle.

Field type supported	Anything that tFields can handle (Blobs included)

Replication method	Field level change recording of change

Collision granularity	Record level (Field level granularity RSN)

Collision detection	For each remote changes, the Master Change Table (MCT)
			is consulted. If anybody touched that record since his last
			connection (implying that he was not current), that change
			is refused.

Collision effect	With record level granularity, Full record reconstruction
			of loosing remote.

Change file format	Format neutral. This means that host and remotes DB image
			formats need not be the same! Ex. ODBC on the host and DBF
			on the remotes.

Change file
Transmission 		All data is zipped before transmission.
			3X to 6X reduction in connect time.

Connection loss		Updates at the host are done in 3 phases.
			 1- Receive change files from remotes
			 2- Apply remote change file and extract those
			   changes needed by that remote.
			 3- Transmit the host change file to the remote
			A loss of connection is registered and next connection
			with that user continues at the proper phase.

User types		Host users and remote users. The host users work
			directly with the master DB image. They never suffer
			collisions. Remote users work with a local DB image and must
			regularly connect with the host for updates

Re-synching remotes	Remotes can be re-synched any time at the remote's request.

User file replication	Any file(s) can be marked for replication at the host
			Remote destination directories are configurable by the remote
			user.

Security		ASCII user list, CRC seed, optionnal passwords
			optionnal 2 phase login

Source Code		All source except for the Master Change Table
			component is included.

System support		System Administration program :
			  Easy access to user list, user status, system
			 log and error files, Master change table viewer, etc



			Pricing, availability and other stuff
			_____________________________________

1- We are currently looking for a base installation program to install all those
remote RED applications. Any developper out there have any suggestion? Our goal
is that all you'd have to do is add your application specific stuff (INI, EXE, etc)
to the base RED installation.

2- Current release date is 02/96

3- Pricing (excluding shipping)
	- DevPack (including a 5 remote license) :	 449$ US
          (Will include all but one source file)
	- Additional remote licenses
	  +10 remotes license				 369$ US (per host)
	  +25 remotes license				 789$ US (per host)
	  unlimited remotes license			3295$ US (per host)

 ** Explaination of our pricing strategy
  We had two choices here. We either charged a high fee for unlimited licences
and that meant a high start-up cost for developpers, or we could have a low price
for developpers and charge at project installation time. on a per remote count
basis. We felt the second option was better.

What were doing in fact is giving the developper unlimited distribution
rights for small RED projects (5 or less remotes) and charging for
extra remotes on large projects.



If you need help, or have comments, we can be reached at:

Compuserve 70302,1653
Internet   70302.1653@compuserve.com
Fax   (514)-539-5250

Robert Daignault.
LPL Soft, inc
