Tài liệu Module 7: Business Logic for Disconnected Components ppt

Module 7: Business Logic for Disconnected Components Contents Overview Introduction to Disconnected Business Logic Technologies Demonstration: Queued Components 11 Demonstration: COM+ Events 15 Logical Design of Disconnected Business Logic 19 Physical Design of Disconnected Business Logic 26 Market Purchasing 42 Best Practices 45 Lab 7: Business Logic for Disconnected Components 46 Review 54 Information in this document is subject to change without notice The names of companies, products, people, characters, and/or data mentioned herein are fictitious and are in no way intended to represent any real individual, company, product, or event, unless otherwise noted Complying with all applicable copyright laws is the responsibility of the user No part of this document may be reproduced or transmitted in any form or by any means, electronic or mechanical, for any purpose, without the express written permission of Microsoft Corporation If, however, your only means of access is electronic, permission to print one copy is hereby granted Microsoft may have patents, patent applications, trademarks, copyrights, or other intellectual property rights covering subject matter in this document Except as expressly provided in any written license agreement from Microsoft, the furnishing of this document does not give you any license to these patents, trademarks, copyrights, or other intellectual property  2000 Microsoft Corporation All rights reserved Microsoft, Active Directory, ActiveX, BackOffice, BizTalk, FrontPage, Microsoft Press, MSDN, MS-DOS, PowerPoint, Visio, Visual Basic, Visual C++, Visual InterDev, Visual J++, Visual Studio, Win32, Windows, and Windows NT are either registered trademarks or trademarks of Microsoft Corporation in the U.S.A and/or other countries Other product and company names mentioned herein may be the trademarks of their respective owners Program Managers: Rhy Mednick, Susie Parrent Instructional Designer: Susie Parrent Subject Matter Experts: David Chesnut, Sam Gill (TechnoWiz), Michel Pahud Media Management: David Mahlmann Editing Manager: Lynette Skinner Editor: Mick Alberts, Jennifer Linn Production Manager: Miracle Davis Print Coordinators: Linda Lu Cannon (Write Stuff), Marlene Lambert (Online Training Solutions, Inc.) Build Coordinator: Eric Wagoner Graphic Artist: Scott Serna Test Lead: Eric Myers Manufacturing Manager: John Williams Group Product Manager: Juan Fernando Rivera Lead Product Manager, System Services and Infrastructure: Edward Dudenhoefer Manufacturing Manager: Rick Terek Operations Coordinator: John Williams Manufacturing Support: Laura King; Kathy Hershey Lead Product Manager, Release Management: Bo Galford Group Manager, Courseware Infrastructure: David Bramble General Manager: Robert Stewart Module 7: Business Logic for Disconnected Components iii Instructor Notes Presentation: 90 Minutes Lab: 60 Minutes In the preceding module, “Business Logic for Connected Components,” you introduced students to cooperative processing among synchronous business objects in an enterprise solution This module provides students with an introduction to cooperative processing among business components that are disconnected in time and space After completing this module, students will be able to: ! Describe the design and implementation of disconnected business logic and how to apply design patterns to the design of business logic ! Describe the technologies used in implementing disconnected business logic: COM+ queued components and loosely coupled events (LCE) ! Create a physical design for a queued component ! Create a physical design for event notification Materials and Preparation This section provides the materials and preparation tasks that you need to teach this module Required Materials To teach this module, you need the following materials: ! Microsoft® PowerPoint® file 1910A_07.ppt ! Module 7: Business Logic for Disconnected Components ! Lab 7: Business Logic for Disconnected Components Preparation Tasks To prepare for this module, you should: ! Read all of the materials for this module ! Complete the lab iv Module 7: Business Logic for Disconnected Components Demonstration This section provides demonstration procedures that will not fit in the margin notes or are not appropriate for the student notes Queued ComponentsTo prepare for the demonstration • Review the instructions in the student notes COM+ Events ! To prepare for the demonstration • Review the instructions in the student notes Module 7: Business Logic for Disconnected Components v Module Strategy Use the following strategy to present this module: ! Introduction to Disconnected Business Logic The purpose of this section is to introduce students to the disconnected business logic layer The business needs of an application require its interaction with other business applications Frequently, these interactions can be separated in time and space Two business scenarios can summarize the business requirements for loosely coupled mechanisms: • Response is never required The client’s job is complete when the call has been made and the message or notification is sent This model works well for applications whose only task is input • Immediate response not required In this scenario, the application does not require an immediate response but expects some form of acknowledgement at some time in the future In the topic “The Business Problem,” illustrate disconnected business logic by using SneakerNet as an example Point out that when using SneakerNet you can pass files but you don’t guarantee delivery Contrast this with using Message Queuing, where delivery is guaranteed In the topic “Business Requirements,” illustrate the interaction with the following example If you are planning a trip from San Francisco to Tel Aviv, you can book your flight with Vigor Airlines (VA) and Blue Sky Airlines (BA) VA would be your carrier from San Francisco to London, and BA would be your carrier from London to Tel Aviv VA acts as your primary agent and can confirm your reservation on its flights but cannot confirm your reservations on BA VA can send a message to BA to ask for confirmation The BA system will subsequently confirm or deny your reservation and notify VA accordingly ! TechnologiesThe purpose of this section is to introduce students to Message Queuing, queued components, and COM+ events Spend time demonstrating queued components and COM+ events and answering student questions about these two demonstrations In the topic “Message Queuing,” continue using the VA/BA example to explain the operation of message queuing ! Logical Design of Disconnected Business LogicThe purpose of this section is to introduce students to the two design patterns that can be used in the logical design of disconnected business logic: Observer and Queue In the topic “Queued Components and Transactions,” explain the concept of a transaction in a disconnected logic environment and the need for a compensating transaction You can use the example of VA and BA to explain that if BA returns a denial of a reservation you would need to add to the application a compensating transaction The compensating transaction would reverse the confirmation of a VA flight since it is no longer applicable if the connection from London to Tel Aviv cannot be made vi Module 7: Business Logic for Disconnected Components ! Physical Design of Disconnected Business LogicThe purpose of this section is to introduce students to the physical design considerations of COM+ events and queued components ! Market Purchasing The purpose of this section is to present the logical and physical designs of the disconnected business logic of Market Purchasing and to explain the justification for the choices made By using the Computer Management application, you can present the mpVendors queue that is implemented by Market Purchasing You can also use Component Services to present the Market Purchasing Business Logic COM+ application By running the Monitor, Vendor, and Accounting applications, you can demonstrate how the disconnected logic works in Market Purchasing You can present the Extensible Markup Language (XML) files that are created when the accounting application is used Or you can show how the mpVendors queue receives messages when a vendor sends notifications ! Best Practices The main message presented in this section is to use the power of queues for disconnected business logic While events are important, the fact that you can only use them on-node makes them too restrictive Lab Strategy ! Lab 7: Business Logic for Disconnected Components The purpose of Lab is for students to learn to design disconnected business logic Students probably will not derive answers that correspond exactly to the Market Purchasing design This is acceptable as long as the student answers are justified and reflect the principles discussed in the module Discuss with students their answers to Lab Module 7: Business Logic for Disconnected Components # Overview Topic Objective To provide an overview of the module topics and objectives Lead-in In this module, you will learn about the disconnected business logic layer and how to create a logical design and a physical design for it ! Introduction to Disconnected Business Logic ! Technologies ! Logical Design of Disconnected Business Logic ! Physical Design of Disconnected Business Logic ! Market Purchasing ! Best Practices In Module 6, “Business Logic for Connected Components,” you were introduced to cooperative processing among synchronous business objects in an enterprise solution In this module, the focus shifts to cooperative processing among business components that are disconnected in time and space After completing this module, you will be able to: ! Describe the design and implementation of disconnected business logic and how to use design patterns ! Describe the technologies used in implementing disconnected business logic: COM+ queued components and loosely coupled events (LCE) ! Create a physical design for a queued component ! Create a physical design for event notification Module 7: Business Logic for Disconnected Components # Introduction to Disconnected Business Logic Topic Objective To provide an overview of the section topics and objectives Lead-in ! The Business Problem ! Business Requirements In this section, you will learn what makes up a business logic layer and, in particular, a disconnected business logic layer Disconnected business logic allows logical business objects and physical business components to cooperate even though they are separated by time and perhaps space The temporal separation is called asynchronous behavior This behavior manifests itself in business logic that makes calls on other business logic objects and does not wait for the results In this section, the disconnected business logic layer will be placed in the proper context of the business problem A discussion of the business requirements for disconnected business logic will follow Module 7: Business Logic for Disconnected Components The Business Problem Topic Objective User Services To provide background about the business problem Lead-in In this topic, you will learn about the business problem facing designers that need to implement a business logic layer Facade Layer Web Services Facade External Objects Business Facade Disconnected Business Logic Layer Connected Business Logic Layer Data Access Layer Transactional DAL Nontransactional DAL There are many parts of a system that can be disconnected, or asynchronous Asynchronous requirements must be identified early, and the design must take them into account Asynchronous Behaviors Many aspects of a distributed system not need to be synchronous For example, consider an order being placed by a customer When the customer clicks a button to enter the order, the business logic needs to save the order to a database to record the purchase The business logic also must send the order to the shipping department to ship the goods on the order to the customer However, the customer is not expecting that the order be shipped immediately, nor does the customer need to be aware of how the order is handled internally by the system The only synchronous response expected by the customer is that the order be placed successfully Consequently, the order does not need to be sent to the shipping department immediately It could be placed in a queue until the shipping department gets a chance to process the order Sometimes a system requires asynchronous behavior For example, when a requisition is entered into the Market Purchasing sample application, the requisition is saved If the requisition is greater than a certain amount, it requires manager approval Because no manager can be expected to monitor the system 24 hours a day, the approval must wait until the manager logs on to the Market Purchasing application This behavior is by nature asynchronous and requires disconnected business logic to be implemented Module 7: Business Logic for Disconnected Components Physical Barriers The separation between systems might be so great that synchronous responses might not be feasible Such is the case with business-to-business communication in the Market Purchasing sample application Requisitions are sent to vendors, but the Market Purchasing application cannot assume that vendor systems are always connected and running As a result, some sort of disconnected business logic is necessary to communicate with systems in other businesses Disconnected Business Logic Layer The solution to dealing with asynchronous behavior is to create a disconnected business logic layer The disconnected business logic layer is parallel with the connected business logic layer In other words, the facades call both layers, and each layer uses the data access layer (DAL) The disconnected business logic layer receives requests from the business or Web services facade layer, processes the requests, and passes additional processing to external objects The disconnected business logic components must also implement techniques for retrieving the results from the external objects and pass the results of the processing back to the facade layer ... PowerPoint® file 1910A_07 .ppt ! Module 7: Business Logic for Disconnected Components ! Lab 7: Business Logic for Disconnected Components Preparation Tasks To prepare for this module, you should: !... context of the business problem A discussion of the business requirements for disconnected business logic will follow Module 7: Business Logic for Disconnected Components The Business Problem... Technologies ! Logical Design of Disconnected Business Logic ! Physical Design of Disconnected Business Logic ! Market Purchasing ! Best Practices In Module 6, ? ?Business Logic for Connected Components, ”