Talk:Three-tier (computing)
Discussion of Web development versus traditional meanings
I'm pretty sure the traditional and web development meanings of 3-tier are closely related - did they diverge at any certain point? From memory, most introductory web development books (eg. Beginning PHP4, The Cold Fusion 4 Web Application Construction Kit, etc.) around 2000 went over the 3-tier architecture in the introduction or first chapter.
Does the Theory Work?
In a three-tier model, how easily can a web application can be converted to different types of applications?
For example:
Using Jakarta Tomcat <-> Jave 2 Enterprise Edition <-> Mysql
then change it to Apache 2 Web Server <-> PHP <-> Postgre
What type of web application would it be? Well, let's say it is a movie rental web application.
~AT3
- Changing the business logic is a pain in the .... Changing PHP for Java Servlets & JSP is very difficult, as the programming is quite diferent. Also, as far as I understand PHP combines both presentation and logic on the same page, whereas a Level 2 JSP implementation implements business logic on servlets and presentation on JSP.
- Now regarding the first architecture, it is actually Apache Web Server -> Jakarta Tomcat (Java 2 Enterprise Edition) -> MySQL. The second one is ok. For either of the two, changing for example Apache Web server with MS IIS 4.0 is doable. I have installed IIS with Jakarta. It is also fairly straightfoward to change the database AS LONG AS you use standard ANSI SQL queries.
- So basically the theory holds... as long as you don't change the most important part, the business logic. --Threner 03:29, 29 October 2005 (UTC)
- If you don't the hardest layer to change is generally the business logic, since it can be anything from PHP, ASP, ASP.NET, a Server, JSP, Beans, Cold Fusion, or any number of other custom pieces and will require extensive re-write. If you do the presentation layer correctly that should be easy, and database migraions are not too much of a problem.
- Also be warned that my 3-tier system put much of the business logic in the data tier as stored procs. Fun fun fun. Rhooker1236 11:55, 1 September 2006 (UTC)
Cleanup and merging
For more information on this (and my crazy plans/screw ups) see Talk:Multitier architecture#Cleanup and merging. -- Foofy 07:13, 19 October 2005 (UTC)
3-Tier is important enough that it deserves its own Wikipedia entry.
Re-merged
I just redid the merge going back the other way, to Three-tier (computing) as the parent, per the apparent consensus in discussion but contrary to the tag direction which I don't think anyone noticed... Georgewilliamherbert 04:39, 26 May 2006 (UTC)
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I think the merge was needed and was very nice.
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I think Multi-tier should not be merged with 3-tier because multitier can be 3 or four or more tier based upon the user or client requirements.
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I have a number of observations about the content. I think the MVC comparison material may not be correct. It is architecturally permissible for a front-tier entity (view) to directly use a service of a back-tier entity (model), esp for read-only browsing of data and administrative repair of damaged data. I think the 3-tier architecture originates from PARC in 1979 with the MVC design pattern. Although this was initially only a Smalltalk programming pattern, it established a universal concept that all computing functionality breaks down into three fundamental sets of concerns, which should be separated. Everyone at the time was looking at Smalltalk for new concepts, and I think people working in distribution of computing eventually made the obvious application of MVC to their work, although they may not have given credit. The earliest extensive documentation of a fully developed 3-tier distributed software architecture is the OSCA(TM) and INA literature from Bellcore in the early 1990's. The primary thinker behind these projects was John Mills. OSCA described 3-tier distribution of computing. INA added the concept of building blocks (software modules) with contracts (well-formed interfaces) that expose either a service (service contract) or the ability to configure and monitor a service (management contract), and it borrowed the ANSA concept of a middleware "trading service," an automated advertisement and discovery service for contracts that enabled dynamic formation and reformation of distributed systems. The INA concepts are now known generally as Service-Oriented Architecture, which is a natural enabler of 3-tier distributed software. Whereas the Bellcore projects produced around 2,500 pages of somewhat unaccessable distributed computing literature, the content was distilled into a 180 page requirements document by the TeleManagement Forum in 2001. [I have lots of references and other items, but have never really participated in a wikipedia page before. Someone pls tell me what to do! kirk@shrewsbury.com] Does anyone know what became of Microsoft DNA? —The preceding unsigned comment was added by Jkshrews (talk • contribs) 15:35, 13 December 2006 (UTC). Kirk Shrewsbury 12:50, 24 December 2006 (UTC)
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Multi-tier and three-tier should be combinded. As a student, I have had study questions that make reference to two-tier, three-tier, and n-tier at the same time. Putting it all in one spot makes sense. It is all in one spot in most textbooks, also. Add ing a redirect reference to Multi-tier using the keyword n-tier is helpful, but it needs to be a little clearer that they are the same for CS newbies. Thanks.—The preceding unsigned comment was added by 68.62.46.47 (talk) 19:07, 30 January 2007 (UTC).