臺灣博碩士論文加值系統

電腦演進中的巨大進展是從單一主機系統發展到電腦網路或是所謂的分散
式系統。如此進展我們可以獲得較好的價格/效能比,較高的可靠度及有效
地分享共有設備資源等等。然而,複雜的軟體發展過程卻成為分散式系統
的障礙。本篇論文提出並實作出一個半自動的分散式軟體發展工具,其最
大的優點乃在於可輕易地協助程式設計師非常方便地設計並發展其分散式
的應用程式,經由標準的 X-Window 上的使用者界面選擇,轉換成可在分散
式系統環境上執行的程式,我們稱這個工具軟體程式為「PROTOOL」。當給
定程式設計師所設計的分散式應用程式的基本資料,作為「PROTOOL」的輸
入規格檔案,該程式設計師即可透過「PROTOOL」的使用界面,以系統所能
接受的已分割程式模組檔案輸入,再選擇所欲產生的伺服程式「servers」
為循序式〔iteratives〕或並行式〔concurrent〕及網路部份傳輸 採〔
TCP〕或〔UDP〕後,最後再按下程式產生扭,而此時「PROTOOL」就能根據
使用者預先輸入的所有選擇,輕易的協助使用者產生正確的分散式網路程
式組,該分散式網路程式組是一個「主從架構程式組」(client server
programs)。的好處是:(1)程式設計師經由系統的協助,能輕易設計並發展
其所要的分散式應用程式,使得他發展分散式程式亦如發展傳統程式一樣
容意。(2)產生的主從架構程式也比原本傳統程式更能存取更多的網路資
源及更適當分配資料位置。(3)使用者可任意選擇欲產生的伺服程式「
servers」為循序式〔iterative〕或並行式〔concurrent〕及網路部份ッ
擉顝w採〔ＴＣＰ〕或〔ＵＤＰ〕,並行式伺服程式可同時接受各處不同地
方的客戶程式1「multiple clients」的要求,不論數百甚至數千名。故效
能上比循序式伺服器高出許多,一般工作量大的伺服程式皆採並行式,但撰
寫發展上非常複雜且困難,故有了「PROTOOL」發展程式環境,使用者完全
不必自己撰寫,省去一些擾人的負擔。

The enormous development of computers is from a centralized
sys- tem to a distributed system. There are many benefits from
this development, such as getting better price/performance
ratio,hig-er reliablility, sharing devices,..ect. But the
complex sofware development process is still a heahache for
moving centralized systems to distributed systems. There are
also many extra burden for writing a distributed application
comparing with a sequenti- al application. This thesis presents
a development tool for SUN RPC programming, and we call it"
PROTOOL". Whith PROTOOL's help, the programming of centralized
systems can design and develop their distributed programs very
easily.In ot- her words,through PROTOOL's GUI enviroment on X-
Windows,they can (1) input the configuration files of client(s)
and server which follow the specifications of the system
requirements. (2) choose the communication protocol (tcp or
udp) between client(s) and server, and finally (3) choose the
type of generated server, ei- ther iterative or concurrent.
What are adventages of PROTOOL? The forst advantage is that it
can remove the burden of programming for design complex
distrib- uted client-server program(s). It accepts multiple
client progr- ams as input, while conventional SUN RPC
mechanisms accepts only one client at a time.The second one is
that it can generate not only an iterative server, but also a
high performance concurrent server, while the conventional SUN
RPC mechanism can only gener- ate an iterative server.Iterative
servers are surely less power- ful than concurrent servers.
Concurrent servers are suitable for heavy - loaded servers
which always need to provide faster response time to multiple
clients.