电子科技女学 Software Architecture Design Pattern Univers的aEe中onic Science and Technolopy时C Lecture 5 Distributed Computing Architecture Distributed Architecture 。Middleware Layer Introduction to CORBA Architecture Software Architecture and Design Pattern 1
Software Architecture & Design Pattern Software Architecture and Design Pattern 1 Lecture 5 Distributed Computing Architecture • Distributed Architecture • Middleware Layer • Introduction to CORBA Architecture
电子科技大学 Software Architecture Design Pattern University af Electronic Science and Technoloryf Chim Distributed Architecture A computing platform that supports a hardware system consists of multiple and autonomous computing elements multiple autonomous nodes resources may not be directly accessible software concurrency multiple controls/multiple failure Software Architecture and Design Pattern 2
Software Architecture & Design Pattern Software Architecture and Design Pattern 2 Distributed Architecture A computing platform that supports a hardware system consists of multiple and autonomous computing elements • multiple autonomous nodes • resources may not be directly accessible • software concurrency • multiple controls/multiple failure
电子科技大学 Software Architecture Design Pattern University af Electronic Science and Technoloryf Chim 分布式系统的优点 资源共享(Resource sharing) 一共享硬件和软件资源。 。 开放性(Openness) 一可使用有不同供应商提供的设备和软件。 ·并发性(Concurrency) 一可通过并行处理来增强性能。 。9 缩放性(Scalability) 一可通过增加新的资源来提高生产力。 ,容错(Fault tolerance) 一在出现某个失误之后仍具备继续运行的能力。 Software Architecture and Design Pattern 3
Software Architecture & Design Pattern Software Architecture and Design Pattern 3 分布式系统的优点 • 资源共享（Resource sharing） – 共享硬件和软件资源。 • 开放性（Openness） – 可使用有不同供应商提供的设备和软件。 • 并发性（Concurrency） – 可通过并行处理来增强性能。 • 缩放性（Scalability） – 可通过增加新的资源来提高生产力。 • 容错（Fault tolerance） – 在出现某个失误之后仍具备继续运行的能力
电子州妓女学 Software Architecture Design Pattern University af Electronic Science and Technoloryf Chim 分布式系统的缺点 ·复杂性(Complexity) -分布式系统比集中式系统复杂得多。 。 保密性(Security) 一更易受到外部攻击。 。 可管理性(Manageability) -需要更多的人力来管理系统。 ·不可预见性(Unpredictability) 响应结果难于预料，与系统构造和网络的负载 情况有关。 Software Architecture and Design Pattern 4
Software Architecture & Design Pattern Software Architecture and Design Pattern 4 分布式系统的缺点 • 复杂性（Complexity） – 分布式系统比集中式系统复杂得多。 • 保密性（Security） – 更易受到外部攻击。 • 可管理性（Manageability） – 需要更多的人力来管理系统。 • 不可预见性（Unpredictability） – 响应结果难于预料，与系统构造和网络的负载 情况有关
电子州妓女学 Software Architecture Design Pattern University af Electronic Science and Technoloryf Chim 2.Distributed Architecture Definition A distributed architecture is an architecture supporting the development of applications and services that can exploit a physical architecture consisting of multiple,autonomous processing elements. Those elements do not share primary memory but cooperate by sending messages over the network. Example-Distributed System Key Characteristics: Home banking Credit Approval Application Application .Multiple autonomous components .Components are not shared by all users +Resources may not be accessible Bank branch .Software runs in concurrent processes server Credit Check Service on different processors .Multiple points of control .Multiple points of failure DBMS Solarison AlX on DBMS Server SPARC IBM RS/6000 Server Software Architecture and Design Pattern 5
Software Architecture & Design Pattern Software Architecture and Design Pattern 5