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Chapter 9-12 - Coggle Diagram

- - - - Presentation
      - Abstraction
      - Control
  - - - The View renders the model into a form suitable for interaction, typically a user interface element.
      - Multiple views can exist for a single model for different purposes.
      - A view port typically has a one to one correspondence with a display surface and knows how to render to it.
    - - Receives user input and initiates a response by making calls on model objects
      - Accepts input from the user and instructs the model and a view port to perform actions based on that input
    - - The Model manages the behavior and data of the application domain.
      - The model responds to requests for information about its state
      - Responds to instructions to change state
    - - Simplified System
        
        Controller/View
        
        Takes care of input/output, interface to model
        
        Model
        
        In charge of business logic
    - - Object Diagram
      - Sequence Diagram of MVC-II
- - - - Is a collection of computational and storage devices connected through a communications network
      - In this type of system, data, software, and users are distributed
      - Can be modeled by the client-server architecture, and this forms the basis for multi-tier architectures
  - - - Responsibility separation such as user interface presentation and business logic processing.
      - Reusability of server components
    - - Lack of heterogeneous infrastructure to deal with the requirement changes
      - Security complications
      - Server availability and reliability
      - Testability and scalability
  - - - CORBA Interface Repository (IFR)
        
        Keeps all registered IDL interface information
        
        Types
        
        use in dynamic method invocation
        
        IDL identifiers for clients and server
        
        Method names, arguments
        
        Can be updated by the IDL utility
      - Dynamic Invocation Interface (DII)
        
        Allows a client to dynamically discover the interface at runtime
        
        Generate
        
        Self-contained
        
        Self-described
        
        Can directly access the ORB
        
        Helps clients invoke remote object methods without the support of a stub proxy
      - Dynamic Remote Invocation
        
        Dynamic Invocation Interface (DII)
        
        without knowing its interface information until runtime
        
        allows CORBA clients to use another CORBA object
        
        Dynamic Skeleton Interface (DSI)
        
        ORB (Object Request Broker) to issue requests to objects
        
        Implemented independently
        
        No compile-time knowledge of their implementation
        
        The only invocation mode available in the early version of CORBA
      - Dynamic Skeleton Interface (DSI)
      - Static Remote Invocation
        
        Is an open standard for distributed, remote-method invocation computing schemes
        
        Provides platform and language independent middleware to integrate distributed applications, including legacy code
        
        Services and Operations
        
        Interface Definition Language (IDL)
        
        Clients can make requests without knowing the detailed implementation and location of the CORBA objects
        
        Compiled into a stub and a skeleton by the IDL compile
        
        The Object Request Broker (ORB)
        
        Provides a software bus on the network for brokering the requests from clients and the responses from servers
        
        Supports increased interoperability with other implementations
        
        CORBA object IDL specifications
        
        Compiled into a stub and a skeleton by the IDL compiler
        
        The stub is deployed on the client-side
        
        The skeleton is deployed on the server-side
    - - Stub (client-side proxy)
        
        Mediates between the client and the broker and provides additional transparency between them
        
        The proxy hides the interprocess communication at protocol level, marshals parameter values, and unmarshals results from the server
        
        Generated at the static compilation time and deployed to the client-side to be used as a proxy for the client.
      - Skeleton (server-side proxy)
        
        Is also statically generated by the service interface compilation and then deployed to the server-side
        
        Encapsulates low-level system-specific networking functions
        
        Receives and unpacks the requests, unmarshals the method arguments, and calls the appropriate service
        
        Receives the result back from the server it also marshals the result before sending it back to the client
      - Broker
        
        Coordinates communications, passing on requests and returning replies
        
        Stares all servers’ registration information, including their functionality and services as well as location information
        
        Provides APIs for clients to request, servers to respond, registering or unregistering server components, transferring messages, and locating servers.
      - Bridges
        
        Are optional components used to hide implementation details when two brokers interoperate
        
        Encapsulate underlying network detail implementation and mediate different brokers
        
        Translate requests and parameters from one format to another
        
        Connect two different networks based on different communication protocols
      - Network
        
        Connects components using designated protocol standards
        
        The request carries data in a message document or method invocation format
    - - Changeability and extensibility
      - Simplicity for clients to access server and server portability
      - Server component implementation and location transparency
      - Reusability
      - Interoperability via broker bridges
      - Feasibility of runtime changes of server components (add or remove server components on the fly)
    - - Low fault-tolerance
      - Difficulty in testing due to the amount of proxies
      - Inefficiency due to the overhead of proxies
  - - - Is still the user interface presentation tier
    - - Manages business logic and execution
    - - Usually handles database management