A 15:12 15/11/01 -0800, vous avez écrit : >Can someone please explain this to me >or where i can find some information >on this.
at the beginning was the 1 tier system : one computer with one or more ttys. all the processing was done in one machine. then computers began to communicate and the 2 tier system appeared : one server or more and one or several clients. some part of the processing was done by the client and the remainder by the server. an obvious example is an application running on a pc requesting data from a database server. user/client applications grew in size and complexity and lead to the symptom known as "fat client" : in some cases the client machines had to be bigger than the server one ! then a question raised : why have the clients do almost all the process ? the 3 tier architecture came : clients doing requests to "intermediate" servers that do requests to "base" servers. usually : client/application/database. so the client process kept only presentation/human interface tasks, while the intermediate servers did the hard job. that's why you can hear about "thin client" technology. just one more thing : you can have 2 tiers or even 3 running on the same machine (example if you have a database server on a machine you generally have a local client to access it). often the app server and the database server run on the same machine, until it's overloaded. then the app server can be moved to a new machine very easily. there's a lot of possible scenarii. there's a trend now to try and use only standard clients (typically web browsers) and standard protocols (HTTP, xDBC, ...). hth - * - * - * - * - * - * - Bien sûr que je suis perfectionniste ! Mais ne pourrais-je pas l'être mieux ? Thierry ITTY eMail : [EMAIL PROTECTED] FRANCE _______________________________________________ Redhat-list mailing list [EMAIL PROTECTED] https://listman.redhat.com/mailman/listinfo/redhat-list