6. Application Server Issues for the Project: CSEP 545 Transaction Processing for E-Commerce
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6. Application Server Issues for the Project CSEP 545 Transaction Processing for E-Commerce Philip A. Bernstein Copyright ©2012 Philip A. Bernstein 1/25/12
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Requests • A request is a message that describes a unit of work for the system to execute. • An application server coordinates the flow of requests between message message sources (displays, applications, applications, etc.) and application programs that run requests as transactions. • Basic control flow: – Translate – Translate the display input (form/menu (for m/menu selection, etc.) into a standard-format request – Send – Send the request to the appropriate server based on the transaction type in the request header – Start – Start the transaction – Invoke the transaction type’s application program program – Commit and send the transaction’s output to the display display 1/25/12
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Application Server Architecture Architecture • App server should make the previous control flow scale up • Bold lines carry request messages 6 1
Web Server 2
5
Request Controller 3
Transaction Server Resource Manager 1/25/12
4
intranet
other TP systems
Transaction Server Resource Manager 3
Application Server Components • Web Browser – A smart device, with forms, menus, input validation
• Web server – Performs front-end front-end work, e.g., security, data caching, …. …. – “Calls” the web page associated with the URL, URL, which in turn calls a request controller
• Request controller (= Workflow Controller in the project) – Calls Start, Commit, and Abort – App logic that transforms the request (automatic loan payment, money transfer) into calls on basic objects (loan, account). • Sometim Sometimes es called business rules.
• Transaction server – Business objects (customer, account, loan, teller)
• Resource Manager – Manager – usually usually a database (DB) system 1/25/12
4
Project’s Process Architecture 1 1 Web Browser Client Web Server
Request Controller Workflow Controller
Transaction Server
Resource Manager
Resource Manager 1/25/12
5
1
Requests • A request is a message that describes a unit of work for the system to execute. • An application server coordinates the flow of requests between message message sources (displays, applications, applications, etc.) and application programs that run requests as transactions. • Basic control flow: – Translate – Translate the display input (form/menu (for m/menu selection, etc.) into a standard-format request – Send – Send the request to the appropriate server based on the transaction type in the request header – Start – Start the transaction – Invoke the transaction type’s application program program – Commit and send the transaction’s output to the display display 1/25/12
2
Application Server Architecture Architecture • App server should make the previous control flow scale up • Bold lines carry request messages 6 1
Web Server 2
5
Request Controller 3
Transaction Server Resource Manager 1/25/12
4
intranet
other TP systems
Transaction Server Resource Manager 3
Application Server Components • Web Browser – A smart device, with forms, menus, input validation
• Web server – Performs front-end front-end work, e.g., security, data caching, …. …. – “Calls” the web page associated with the URL, URL, which in turn calls a request controller
• Request controller (= Workflow Controller in the project) – Calls Start, Commit, and Abort – App logic that transforms the request (automatic loan payment, money transfer) into calls on basic objects (loan, account). • Sometim Sometimes es called business rules.
• Transaction server – Business objects (customer, account, loan, teller)
• Resource Manager – Manager – usually usually a database (DB) system 1/25/12
4
Project’s Process Architecture 1 1 Web Browser Client Web Server
Request Controller Workflow Controller
Transaction Server
Resource Manager
Resource Manager 1/25/12
5
