ERP Course: Enterprise Application Integration Readings: Chapter 3 from Gustavo Alonso et al Peter Dolog dolog [at] cs [dot] aau [dot] dk 5.2.03 Information Systems November 11, 2008
2 IS/ERP IS/ERP IS/ERP IS/ERP IS/ERP supplier and customer mgmt quotation order processing procurement shipment management financial
top-down design 1. define access channels and client platforms Historical Perspective 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 client presentation layer application logic layer resource management layer information system 3
3-tier architecture client presentation layer application logic layer resource management layer middleware information system 4
client Web browser N-tier architecture Web server HTML filter application logic layer presentation layer middleware information system resource management layer 5
Blocking/Synchronous Communication invoking execution thread request invoked execution thread blocking period response 6
Nonblocking/Asynchronous Communication invoking execution thread invoked execution thread queue thread remains active put fetch fetch put queue 7
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 8
RPC client client process server server process procedure call procedure client stub bind marshal serialize send communication module server stub unmarshal deserialize receive dispatcher (select stub) communication module 9
client 1. BOT 4. procedure call 10. EOT client process server 9. procedure server process client stub 2.register txn & create context 5.add txn id & context to call 11.request commit 14.confirm termination server stub 6. extract context and txn id 7. register server for txn 13. participate in 2PC 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 transaction manager 10
11 Other Middleware Object brokers Object monitors Message-oriented middleware Message brokers
Input queue Output queue external application Reliable queuing system Output queue Request Quote Input queue external application Copyright Gustavo Alonso, ETH Support Quote 12
inventory manageme nt ERP dispatcher shipping monthend closing new PO new PO new PO new PO message-oriented middleware 13
in basic MOM it is the sender who specifies the identity of the receivers sender receiver message broker core message broker with message brokers, custom message routing logic can be defined at the message broker level or at the queue level 14
inventory manageme nt (subscrib er) new PO ERP (subscrib er) new PO dispatcher (publisher) new PO shipping (subscrib er) new PO monthend closing (subscrib er) new PO message broker 15
administrative domain A administrative domain C admi n clie nt clie nt admi n clie nt clie nt message broker MB-A message broker MB-C message broker MB-B admi n clie nt clie nt administrative domain B 16
integrating application (contains the composition logic) message broker SmartQuotation adapter database adapter SmartForecasting adapter e-mail adapter XYZ adapter SmartQuotation DBMS applications SmartForecasting XYZ 17
18 SmartQuotation adapter SmartQuotation RFQ processing A 1 5 6 message broker B 2 4 C 7 3 SmartForecasting adapter 8 SmartForecasting 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
19 check if offered product Offered=false check if worth proceeding Offered=true else GoAhead=true ContractExists=false get quote from supplier update quotation system get quote from quotation system ContractExists=true variables: QuoteReferenceNumber: int Customer: String Item: String Quantity: int RequestedDeliveryDate: Date DeliveryAddress: String GoAhead: Bool ContractExists: Bool Offered: Bool send quote to customer enter quote in forecasting system
resource broker resource 1 completed work items 1 3 workflow engine 4 5 resource 2 inbound queue 2 resource n workflow designer workflow definitions outbound queues 20
Copyright Gustavo Alonso, ETH 21