ERP Course: Enterprise Application Integration Readings: Chapter 3 from Gustavo Alonso et al Peter Dolog dolog [at] cs [dot] aau [dot] dk E2-201 Information Systems November 15, 2006

2 Peter Dolog, ERP Course, EAI Copyright Springer Verlag Berlin Heidelberg 2004 IS/ERP

3 Peter Dolog, ERP Course, EAI Historical Perspective presentation layer resource management layer application logic layer client information system 1. define access channels and client platforms 2. define presentation formats and protocols for the selected clients and protocols 3. define the functionality necessary to deliver the contents and formats needed at the presentation layer 4. define the data sources and data organization needed to implement the application logic top-down design Copyright Springer Verlag Berlin Heidelberg 2004

4 Peter Dolog, ERP Course, EAI client presentation layer resource management layer application logic layer information system 3-tier architecture middleware Copyright Springer Verlag Berlin Heidelberg 2004

5 Peter Dolog, ERP Course, EAI client resource management layer application logic layer information system N-tier architecture middleware presentation layer Web server Web browser HTML filter Copyright Springer Verlag Berlin Heidelberg 2004

6 Peter Dolog, ERP Course, EAI request response invoking execution thread invoked execution thread blocking period Copyright Springer Verlag Berlin Heidelberg 2004 Blocking/Synchronous Communication

7 Peter Dolog, ERP Course, EAI Nonblocking/Asynchronous Communication put invoking execution thread invoked execution thread queue fetch queue thread remains active Copyright Springer Verlag Berlin Heidelberg 2004

8 Peter Dolog, ERP Course, EAI RPC Abstraction Remote Procedure Call sockets TCP, UDP Internet Protocol (IP) Remote Procedure Call: hides communication details behind a procedure call and helps bridge heterogeneous platforms sockets: operating system level interface to the underlying communication protocols TCP, UDP: User Datagram Protocol (UDP) transports data packets without guarantees Transmission Control Protocol (TCP) verifies correct delivery of data streams Internet Protocol (IP): moves a packet of data from one node to another Copyright Springer Verlag Berlin Heidelberg 2004

9 Peter Dolog, ERP Course, EAI RPC communication module client procedure call client stub bind marshal serialize send client process communication module server procedure server stub unmarshal deserialize receive server process dispatcher (select stub) Copyright Springer Verlag Berlin Heidelberg 2004

10 Peter Dolog, ERP Course, EAI client 1. BOT 4. procedure call 10. EOT client stub 2.register txn & create context 5.add txn id & context to call 11.request commit 14.confirm termination client process server 9. procedure server stub 6. extract context and txn id 7. register server for txn 13. participate in 2PC server process transaction manager 3. create txn id register txn register client for txn return txn id 8. lookup txn id register server for txn 12. lookup txn id run 2PC notify client of outcome Copyright Springer Verlag Berlin Heidelberg 2004

11 Peter Dolog, ERP Course, EAI Other Middleware Object brokers Object monitors Message-oriented middleware Message brokers

12 Peter Dolog, ERP Course, EAI external application Input queue Input queue Output queue Output queue Reliable queuing system Request Quote Support Quote Copyright Gustavo Alonso, ETH

13 Peter Dolog, ERP Course, EAI dispatcher inventory manageme nt ERPshipping message-oriented middleware month- end closing new PO Copyright Springer Verlag Berlin Heidelberg 2004

14 Peter Dolog, ERP Course, EAI message broker core senderreceiver message broker with message brokers, custom message routing logic can be defined at the message broker level or at the queue level in basic MOM it is the sender who specifies the identity of the receivers Copyright Springer Verlag Berlin Heidelberg 2004

15 Peter Dolog, ERP Course, EAI dispatcher (publisher) inventory manageme nt (subscrib er) ERP (subscrib er) shipping (subscrib er) message broker month- end closing (subscrib er) new PO Copyright Springer Verlag Berlin Heidelberg 2004

16 Peter Dolog, ERP Course, EAI admi n message broker MB-A message broker MB-B clie nt … admi n clie nt … admi n message broker MB-C clie nt … administrative domain A administrative domain B administrative domain C Copyright Springer Verlag Berlin Heidelberg 2004

17 Peter Dolog, ERP Course, EAI DBMS applications message broker SmartQuotation adapter adapter database adapter SmartQuotation SmartForecasting adapter SmartForecasting XYZ adapter XYZ integrating application (contains the composition logic) Copyright Springer Verlag Berlin Heidelberg 2004

18 Peter Dolog, ERP Course, EAI message broker SmartQuotation adapter SmartQuotation SmartForecasting adapter SmartForecasting RFQ processing 1A6 BC at systems startup time (can occur in any order, but all must occur before RFQs are executed) A: subscription to message quote B: subscription to message quoteRequest C: subscription to message newQuote at run time: processing of a request for quote. 1: publication of a quoteRequest message 2: delivery of message quoteRequest 3: synchronous invocation of the getQuote function 4: publication of a quote message 5: delivery of message quote 6: publication of a newQuote message 7: delivery of message newQuote 8: invocation of the createForecastEntry procedure Copyright Springer Verlag Berlin Heidelberg 2004

19 Peter Dolog, ERP Course, EAI check if offered product check if worth proceeding get quote from quotation system get quote from supplier enter quote in forecasting system send quote to customer ContractExists=true ContractExists=false Offered=true Offered=false GoAhead=true update quotation system variables: QuoteReferenceNumber: int Customer: String Item: String Quantity: int RequestedDeliveryDate: Date DeliveryAddress: String GoAhead: Bool ContractExists: Bool Offered: Bool else Copyright Springer Verlag Berlin Heidelberg 2004

20 Peter Dolog, ERP Course, EAI workflow engine resource broker completed work items inbound queue resource 1 resource 2 resource n workflow definitions outbound queues workflow designer Copyright Springer Verlag Berlin Heidelberg 2004

21 Peter Dolog, ERP Course, EAI Copyright Gustavo Alonso, ETH