Distributed Database System-Implementation of business travel booking system (1)

Today, I saw my younger siblings busy with course completion design as we did last year, thinking about how I worked hard last year and sharing my development experience.

Project Introduction

This system is designed based on the distributed database course. On the Microsoft Visual Studio 2010 Development Platform, a distributed application system is built using the C # language to implement a simple distributed travel booking system. As required, the system implements three basic functions: A simple Resource Manager (RM) that supports concurrent transactions with acid attributes and a workflow manager (WC) and a Transaction Manager (TM) can implement distributed transaction processing among various resource managers (RM), and implement external adding functions for these basic projects. The system provides a visual interface for human-computer interaction, including querying, inserting, and booking.

The Distributed Database technology is used to implement a travel booking system, which can be used to query (flights, hotels, taxis, customers, reservations), insert (aircraft-related information, hotel-related information, taxi-related information, customer-related information), booking (travel information ). Logically, all information is stored in the same database. Physical, flight, taxi, hotel, customer, and reservation information are stored on different sites.

Main technologies

Remoting, in short, can be seen as a distributed processing method. From the perspective of Microsoft products, it can be said that remoting is an upgrade of DCOM, which improves many functions and is well integrated into the. NET platform. Microsoft. NET remoting provides a framework that allows an object to interact with another object through an application domain. This is exactly why remoting is used. Why? In Windows, applications are separated into separate processes. This process forms a boundary around the application code and data. If the inter-process communication (RPC) mechanism is not used, the Code executed in one process cannot access another process. This is an operating system's protection mechanism for applications. However, in some cases, We need to cross the application domain and communicate with another application domain, that is, cross the border.

In remoting, a channel is used to implement object communication between two application domains. First, the client uses remoting to access the channel to obtain the server object, and then parses it as the client object through proxy. This provides a possibility to publish server objects as a service. Remote Object code can run on a server (such as an object activated by the server and an object activated by the client). Then, the client connects to the server through remoting to obtain the service object and serialize it to the client.

In remoting, in addition to the channel type and port number, the designer does not need to know the data packet format for the objects to be transmitted. However, it must be noted that when obtaining the server-side object, the client does not obtain the actual server-side object, but obtains its reference. This ensures loose coupling between client and server objects, and optimizes communication performance.