Demaq: A Foundation for Declarative XML Message Processing

Transcription

1 : A Foundation for Declarative Message Processing Alexander Böhm Carl-Christian Kanne Guido Moerkotte University of Mannheim Carl-Christian Kanne, January 8, p. 1/20

2 Messaging Messaging Networks of s Messaging Rules -tier Architectures State of the Art Customer Supplier A Manufacturer Supplier B Customer Supplier C SOA, Web Services, AJAX, RSS/Atom... Carl-Christian Kanne, January 8, p. 2/20

3 Networks of s Messaging Networks of s Messaging Rules -tier Architectures State of the Art Carl-Christian Kanne, January 8, p. 3/20

4 Messaging Rules Messaging Networks of s Messaging Rules -tier Architectures State of the Art "If a request for an offer comes in, forward it to the legal, finance, and planning departments" "If the delivery of all items has been confirmed, send a completion message to the customer" Carl-Christian Kanne, January 8, p. 4/20

5 -tier Architectures Messaging Networks of s Messaging Rules -tier Architectures State of the Art Messaging System Network App Server App Code TP Monitor Java Java Java C# C# DBMS Carl-Christian Kanne, January 8, p. 5/20

6 State of the Art Messaging Networks of s Messaging Rules -tier Architectures State of the Art t o p i c = ( ( QIjmsSession ) t_sess ). gettopic ( " strmadmin ", " oe_queue " ) ; t_pub = t_sess. c r e a t e Publisher ( t o p i c ) ; db_conn = ( ( QIjmsSession ) t_sess ). getdbconnection ( ) ; agent = new QIjmsAgent ( " e x p l i c i t _ e n q ", n u l l ) ; adt_msg = ( ( QIjmsSession ) t_sess ). createadtmessage ( ) ; l c r _ d a t a = new S t r i n g B u f f e r ( ) ; l c r _ d a t a. append (" <ROW_LCR " ) ; l c r _ d a t a. append ( " xmlns = h t t p : / / xmlns. t e n t a c l e. com / streams / schemas / l c r " ) ; l c r _ d a t a. append ( " xmlns : x s i = h t t p : / / www. w3. org /2001/Schema instance " ) ; l c r _ d a t a. append ( " x s i : schemalocation = h t t p : / / xmlns. t e n t a c l e. com / streams / schemas / l c r " ) ; l c r _ d a t a. append ( " h t t p : / / xmlns. t e n t a c l e. com / streams / schemas / l c r / s t r e a m s l c r. xsd > " ) ; l c r _ d a t a. append (" < source_database_name>source_dbname </ source_database_name > " ) ;... MORE DOCUMENT CONSTRUCTION HERE... x m l _ l c r = t e n t a c l e. xdb. Type. create ( db_conn, l c r _ d a t a. t o S t r i n g ( ) ) ; adt_msg. setadtpayload ( x m l _ l c r ) ; ( ( QIjmsMessage) adt_msg ). setsenderid ( agent ) ; System. out. p r i n t l n ( " Publish message 3 Type c o n t a i n i n g LCR ROW" ) ; r e c i p L i s t = new QIjmsAgent [ 1 ] ; r e c i p L i s t [ 0 ] = new QIjmsAgent ( " e x p l i c i t _ d q ", n u l l ) ; ( ( QIjmsTopicPublisher ) t_pub ). p u b l i s h ( t o p i c, adt_msg, r e c i p L i s t ) ; t_sess. commit ( ) ; Carl-Christian Kanne, January 8, p. 6/20

7 Application Application Application Language(s) Network QML Rules Sample Rule Server Messages all the way Project Thank you Complete Declarative Executable Carl-Christian Kanne, January 8, p. 7/20

8 Language(s) Application Application Language(s) QML Rules Sample Rule Server Messages all the way Project Thank you Application Rules (QML) Network Message s (QDL) Language Carl-Christian Kanne, January 8, p. 8/20

9 QML Rules Application Language(s) QML Rules Sample Rule Server Messages all the way Project Thank you "If the delivery of all items has been confirmed, send a completion message to the customer" Carl-Christian Kanne, January 8, p. 9/20

10 QML Rules Application Language(s) QML Rules Sample Rule Server Messages all the way Project Thank you "If the delivery of all items has been confirmed, send a completion message to the customer" messages new messages Carl-Christian Kanne, January 8, p. 9/20

11 QML Rules Application Language(s) QML Rules Sample Rule Server Messages all the way Project Thank you "If the delivery of all items has been confirmed, send a completion message to the customer" XQuery Update Facility + Queuing Primitives messages new messages Carl-Christian Kanne, January 8, p. 9/20

12 Sample Rule Application Language(s) QML Rules Sample Rule Server Messages all the way Project Thank you create r u l e sendcomplete f o r ordermsgs i f ( / / deliverymsg = " confirm " ) then l e t $ordered := fn : count ( qs : s l i c e ( ) / / ordermsg / / item ) l e t $ d e l i v e r e d := fn : count ( qs : s l i c e ( ) / / deliverymsg / item ) where $ordered eq $ d e l i v e r e d return do enqueue <done> { / / orderid } </done> into customerreply Carl-Christian Kanne, January 8, p. 10/20

13 Server Application Application Language(s) QML Rules Sample Rule Server Messages all the way Project Thank you Application Rules (QML) Network Transport Rule Message s (QDL) Engine Transactional Store Language Server Carl-Christian Kanne, January 8, p. 11/20

14 Messages all the way Application Language(s) QML Rules Sample Rule Server Messages all the way Project Thank you Everything is an message Rule Input Rule Output Errors Timeouts Messages are processed once, but kept "forever" Message History captures process state organized into slices (virtual queues) declarative expiration Carl-Christian Kanne, January 8, p. 12/20

15 Project Application Application Language(s) QML Rules Sample Rule Server Messages all the way Project Thank you Application Rules (QML) QEP Network Transport QEP Rule Message s (QDL) QEP Engine Transactional Store Language Compiler Server Carl-Christian Kanne, January 8, p. 13/20

16 Thank you Application Language(s) QML Rules Sample Rule Server Messages all the way Project Thank you Carl-Christian Kanne, January 8, p. 14/20

17 Slices Requests Slices Slice usage Error Handling A Rule Work in progress Goals Delivery Notifications Orders 7... s Slices Slice for customer 23 Slice for customer 42 create property customerid f i x e d queue requests, orders, d e l i v e r y N o t i f i c a t i o n s value / / customerid create s l i c i n g customers on customerid Carl-Christian Kanne, January 8, p. 15/20

18 Slice usage Slices Slice usage Error Handling A Rule Work in progress Goals Merge parallel control flow Check Credit Rating Check Export Restrictions Check Plant Capacity Check Setup Costs Send/Refuse Offer create property c o r r e l a t i o n I D fixed queue creditcheck, exportcheck, plantcheck, setupcheck value / / c o r r e l a t i o n I D create s l i c i n g checkresults on c o r r e l a t i o n I D create rule merge for checkresults i f ( count ( qs : s l i c e ( ) ) eq 4) then... Carl-Christian Kanne, January 8, p. 16/20

19 Error Handling Slices Slice usage Error Handling A Rule Work in progress Goals Plenty of error sources in distributed applications Application-related (dynamic errors) Message-related (invalid, wrong schema) Network-related (disconnects, routing,... )... Message-based error handling Error queues, e.g. for rules create rule errorsource for foo errorqueue e r r o r s Carl-Christian Kanne, January 8, p. 17/20

20 A Rule Slices Slice usage Error Handling A Rule Work in progress Goals create r u l e newofferrequest f o r customermsgs i f ( / / offerrequest ) then l e t $customerinfo := <requestcustomerinfo reqid = " { / / requestid }" > <customer > { / / customerid } < / customer > </ requestcustomerinfo > l e t $ e x p o r t R e s t r i c t i o n I n f o :=... l e t $ p l a n t C a p a c i t y I n f o :=... return do enqueue $customerinfo into finance, do enqueue $ e x p o r t R e s t r i c t i o n s I n f o into l e g a l, do enqueue $ p l a n t C a p a c i t y I n f o into s u p p l i e r Carl-Christian Kanne, January 8, p. 18/20

21 Work in progress Slices Slice usage Error Handling A Rule Work in progress Goals Optimization across rules Optimization/verification across sites Template Folding [XIMEP06] Rules driven by Schema validation Carl-Christian Kanne, January 8, p. 19/20

22 Goals Slices Slice usage Error Handling A Rule Work in progress Goals Declarative message processing language Move work from programmer to system Data independence Optimizable Execution Engine Reliability Scalability Reuse DB system knowledge Carl-Christian Kanne, January 8, p. 20/20