Transaction and Rule Support for Workflow Management - A Retrospective on the WIDE Architecture Paul...
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Transcript of Transaction and Rule Support for Workflow Management - A Retrospective on the WIDE Architecture Paul...
Transaction and Rule Supportfor Workflow Management -A Retrospective on the WIDE
Architecture
Paul GrefenCS Department & CTIT
University of Twente
Workflow on IntelligentDistributed database
Environment
DBMS
WFMS
WFAM
TT
DBMS
DBMS EXT.
WFMS
WFA
MT
TW
IDE
Ap
pro
ach
• Extended transaction support– Loose global transactions (saga)– Strict local transactions (nested)
• Active rule support– Decoupled execution mode– Workflow, data, external, time events
• Data support– Object-oriented client interface– Relational server interface– IDL-SQL/C++ compiler support
DB
MS
Ext
ensi
ons
• Advanced data support versus workflow support– reusability of advanced data support
• Extended transaction support versusactive rule support– orthogonal and flexible semantics– adaptability of transaction/rule support
• WIDE integrated workflow system vs.commercial DBMS– portability of WIDE WFMSO
rth
ogon
al A
rch
itec
ture
DBMS
BAL
WorkflowEngine
TransactionSupport
Active RuleSupport
WorkflowClient
Ove
rall
WID
E A
rch
itec
ture
orthogonalityorth
ogonality
DistributionDistribution
WorkflowEngine
BAL
DBMS
LTM
Local Trans.Interface
GlobalTrans. Man.
GTLT
Tra
nsa
ctio
n S
up
por
t
CORBA
OCI
WorkflowEngine
Interpreter
Scheduler
TimeManager
Ext. EventManager
ExternalApplications
BAL
Oracle TS Events
Act
ive
Ru
le S
up
por
t
• Commercial RDBMS (Oracle 7.2)– Robust basic data support– Flat ACID transactions, basic triggers– Client/Server coupling (OCI)
• CORBA (ILU)– Flexible distribution– Transparent communication
Infr
astr
uct
ure
• Functionality– Does the system do what was intended?
• Performance– Does the system offer reasonable
performance?
• Maintainability– Is the system easy to implement and
modify?
Loo
kin
g B
ack
at
the
Des
ign
• Local transaction functionality– Limited flexibility for atomicity control– Limited transactional multi-DB access– X/Open TPM extension helps
• Rule execution functionality– Decoupled rule execution model– Orthogonal transaction/rule semantics– Limited intra-business transaction rules
Fu
nct
ion
alit
y in
Ret
rosp
ect
• C/S connection to DBMS critical– Large numbers of small transactions– Physical channel creation expensive– Reuse already created channels– Keep channels in channel pool– Modification local to LTI– Further extensions possible:
• channel creation in idle time
• statistical forecasting of channel usage
Per
form
ance
in R
etro
spec
t
• Software development in 3 organizations– Sema (ES), POLI (IT), UT (NL)
• High level of flexibility required
• Orthogonal architecture design
• Standard internal module architectures
• CORBA/IDL interface specification
• Empty Shell integration
• Complexity may lead to semantic problems though ….
Mai
nta
inab
ilit
y in
Ret
rosp
ect
• Transfer of WIDE technology to FORO commercial WFMS(SEMA)
• Use of transaction concepts in cross-organizational contexts(UT, CrossFlow project)
• Unbundling of active rule engine functionality for non-WFM purposes(POLI, SEMA)
• Book on WIDE developments(Kluwer Academic, January ‘99)F
urt
her
Dev
elop
men
ts