Very Computer

by **Eric Buckle** » Wed, 20 Aug 1997 04:00:00

<snip>

Quote:> 3-Tier client server has the GUI application requesting data from an
> intermediate layer (the business services layer) and the intermediate tier
> accessing the database.

I would add that, to be meaningful, this tier should be enforcing some
sort of enterprise-wide business rules. Examples of these are
consistency rules, calculated fields, triggers, etc.. The merits of this
are that your business rules are put in one place where they can be
consistently enforced. Do not underestimate the amount of work required
to set this up properly.
________________________
Eric Buckley
Comsys Millennium Services
eMail: remove NoSpam from above
Standard disclaimer - I speak for myself and nobody else.

by **Janine8** » Wed, 20 Aug 1997 04:00:00

Can someone please explain to me the difference between Tier 2 & Tier 3
Client Server Architecture.

Any info would be greatly appreciated.

by **Roderick Princ** » Wed, 20 Aug 1997 04:00:00

Janine,

IMHO...

2-Tier client server consists of a GUI Application directly accessing data
from a local/remote database. Depending on who you talk to it might also
include the calling of stored procedures.

3-Tier client server has the GUI application requesting data from an
intermediate layer (the business services layer) and the intermediate tier
accessing the database.

n-Tier client server has the middle tier acting as both a server to GUI
application and as a client to other business services.

Happy trails,
Roderick...

http://www.aerial.net

Janine802 wrote in article

Quote:>Can someone please explain to me the difference between Tier 2 & Tier 3
>Client Server Architecture.

>Any info would be greatly appreciated.

by **Foued Marzouk** » Thu, 21 Aug 1997 04:00:00

> Can someone please explain to me the difference between Tier 2 & Tier 3
> Client Server Architecture.

> Any info would be greatly appreciated.

try this for answers

http://www.cis.ohio-state.edu/hypertext/faq/usenet/client-server-faq/...

by **Alan Gaul** » Thu, 21 Aug 1997 04:00:00

> I would add that, to be meaningful, this tier should be enforcing some
> sort of enterprise-wide business rules. Examples of these are
> consistency rules, calculated fields, triggers, etc.. The merits of this
> are that your business rules are put in one place where they can be
> consistently enforced. Do not underestimate the amount of work required
> to set this up properly.

That's one application of an intermediate server. Another is to provide
a common processor intensive service. eg Fast Fourier analysis functions
etc working on data sets from the 3rd teir. Fourier transforms are not
business rules but the processing may well be best placed on a fast
unix workstation or similar...

Another often neglected aspect of 3 teir is that the mid teir servers
may infact use other mid-teir services to perform their role. Thus
processing
goes:

Client - Mid Teir Service(MTS)1 - MTS2 - MTS3 - Third Teir(Database).

This would be likely if security validation of transactions were
implemented via a security server say...

Alan G.

by **Roderick Princ** » Thu, 21 Aug 1997 04:00:00

<SNIP>

Quote:>Another often neglected aspect of 3 teir is that the mid teir servers
>may infact use other mid-teir services to perform their role. Thus
>processing
>goes:

>Client - Mid Teir Service(MTS)1 - MTS2 - MTS3 - Third Teir(Database).

>Alan G.

<SNIP>

In order to clarify these types of relationships they are sometimes referred
to as "n-Tier Client/Server" systems.

Happy trails,
Roderick...

http://www.aerial.net

by **Eclyps** » Fri, 22 Aug 1997 04:00:00

You can get a very nice white paper about that on www.trcinc.com

Regards,
Peter Boey
Nike

> Can someone please explain to me the difference between Tier 2 & Tier 3
> Client Server Architecture.

> Any info would be greatly appreciated.

Very Computer

Tier 2 vs Tier 3 Client Server Architecture

Tier 2 vs Tier 3 Client Server Architecture

Tier 2 vs Tier 3 Client Server Architecture

Tier 2 vs Tier 3 Client Server Architecture

Tier 2 vs Tier 3 Client Server Architecture

Tier 2 vs Tier 3 Client Server Architecture

Tier 2 vs Tier 3 Client Server Architecture

Tier 2 vs Tier 3 Client Server Architecture