以元件為組成基礎之分散式系統的計算與通訊最佳化

Computation and Communication Optimizations for Component-based Distributed Systems

陳崇凱(Chung-Kai Chen)

指導教授 ： 李政崑

國立清華大學/電機資訊學院/資訊工程學系/博士(2008年)

https://doi.org/10.6843/NTHU.2008.00603

摘要

以元件為基礎的軟體技術與架構隨著網際網路和Internet的成長而越來越熱門，其成功來自於幾個因素的結合，其中包括物件導向技術帶來的抽象化，把實做與介面分離，以及公開的元件架構，使應用程式的合作更易建立，而使用可再利用的軟體元件也使得軟體的複雜度得以管理，透過動態的元件組合變化可以使得軟體更具彈性與擴充力。當我們享用這些元件技術帶來的好處時，未來仍有許多挑戰，來自於這樣的新的電腦運算架構：由一個具有自主管理能力，類似Grid的次系統，將由各個元件組合成的分散式應用程式連結起來。在本篇論文中我們認為除了實做與介面的分離之外，還有額外的資訊需要註記在每個元件身上，這對於將電腦運算提升至下一個新的領域是很重要的，這個軟體元件的規格將能使得元件的使用更切合於執行環境。現有的物件導向技術，已經賦與元件一個基本的規格，也就是它實做的介面，我們認為還需要額外的資訊，來表達某個介面的不同實做元件之間的差異，這些額外的資訊將能幫助我們找到不只是能用的元件，而是適切的元件。除了關於操弄元作來得到較好的效能的討論，這篇論文也包括了許多針對一般元件常使用的通訊協定，如Java的RMI和.Net的Remoting，的研究與工作成果，例如為了在分散式系統中做元件組合的最佳化，當涉及到網路兩端的元件時，元件之間原有的通訊必需要小心的處理，因此我們對於元件的通訊提供了漫遊的支援，其它的研究成果還包括了串流資料的支援以及伺服器端網路處理器的最佳化。

關鍵字

元件最佳化 ； 自主運算 ； 元件調適 ； 行動計算 ； 分散式計算

並列摘要

Component software technologies and architectures have grown with great popularity
along with the advances of web and internet technologies. The successes
are coming from several compound factors. A try in the analysis of these factors
might include abstractions of object-oriented concepts which separates the implementation
from interfaces, open and distributed component architectures which
enables building of cooperative applications, re-usable components which allows
managements of software complex, the possibilities of component compositions
at runtime which makes software more flexible and extensible. While enjoying
great successes, component technologies are with great challenges ahead. This
is in part due to an era of the new arrival of computer architectures including
the distributed enterprise architectures built with individual components linked by
messaging subsystems, the autonomous and grid-like architectures in the web, and
the distributed and pervasive architectures assembled by a group of small devices
and connected by heterogeneous wireless environments.
In this dissertation we argue that additional properties of component software
need to be annotated in addition to the separation of implementations from interfaces.
We think this is important for component software and architectures to
meet the new era of distributed systems. Specifications on software components
will allow the adoption of components best adaptive to given environments. Due
to object-oriented techniques, the component resources have common information
associated with them, the interfaces they implement. We argue that additional
descriptions can be added. These properties, we called metadata, address the difference
between the implementations of the interface. It helps us search not only
the kind of components, but also specific realizations.
In spite of the focus on the performance benefits brought by specifying and
dynamically changing components, this dissertation also presents many works on
providing advanced improvement on commonly used component communication,
such as RMI in Java and Remoting in .NET. For example, to enable the optimization
of runtime component composition described above in a distributed system,
the communication must be handled carefully as well. It is possible that the composition
of components occur involving components in different sites. Thus the
communication between components should act seemly with external changes. A
software layer has been proposed in this dissertation to monitor data transportation.
It leads to the work on the roaming support built-in existing component
communication layers. We further provide many other features to current component
communication methods, which includes embedding data streaming under
the programming paradigm of common component communication, as well as
using network processors as switching support for component communication.

並列關鍵字

Component-based optimization ； Autonomous computing ； Component adaptation ； Mobile computing ； Distributed computing

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