SNU -- KINS
Status of
Mediation Technology
Gio Wiederhold
Stanford University
Oct 1999
Flow in Mediation
•
DELIVERY
t
s
• SUMMARIZATION
t
s
• INTEGRATION
t
s
• ABSTRACTION
t
• ACCESS
s
Example in Health Care
Health Care Planner
Will the Clinic loose Money?
Investment
domain
Patient
Care domain
Age Profile
Service Operations
Patient Volume Growth
Loan Interest
Bond Sales
State Support
Gio Wiederhold. 1995
Evolution of Mediation
applications
A2
A1
A4
A3
A5
A6
integrators
a.
I2
I1
mediators
network
b.
M1
c.
d.
wrappers
D1
W2
W1
D2
D4
D3
datasources
W3
D5
M2
e.
D6
Features of Mediation
• Domain-specific partitioning for
Creation and Maintenance
C
B
A
• Network-basing for easy
Reconfiguration
E
• Caching to deal with
Asynchronocity
A1
• Replication for
Performance
A1’
D
Allocation Flexibility
User Interfaces
Application C
Provider of
Mediator M
Application I
Provider
of mediator N
M
Copy- if high
intensity of
interaction with
1. Application (M2)
2. Resources (N1,2)
3. Processing (M1)
Mediators are
only code
Application B
M2
HPC
N
M1
DB
P
N
2
Databases
N
1
DB
Q
DBS R
Facilitators
Another
Module Type in
Facilitators Procure Linkages
Information
• search for suitable resources
Systems
• resolve terminological mappings
• build system configurations
• issue subqueries, as needed
• combine results from subqueries
perform these tasks dynamically
without human intervention
depend greatly on ontologies
• can call on mediators for value added services
Facilitators and Mediators
accessible
ontology
dynamic
designed
Central Solutions do not Scale
What works
with 7 modules
and one person
in charge
fails when we
have 100 and need
a committee
Changes in resources affect the intermediary modules
Integration at two levels
Application
• Informal, pragmatic
• User-control
Mediation
• Formal service
• Domain-Expert control
Gio Wiederhold. 1995
Status of Mediation Technology
Today
• Handcrafted
• Expert consults with
programmer
• Programmer codes the
knowledge needed
• Resource changes require
advise, program update
Future
• Generated from models
• Domain Expert maintains
models
• Specification determines
functions
• Resource changes trigger
regeneration
Coverage of Current I3 Efforts
(web,schema
searching)
)
for relevance
to customer
Maintenance
(rule technology?)
Integration
over sources
:-)
Wrapping (syntactical heterogeneity)
:-(
Databases / Web / Text / Simulation
:-[
:-(
for cooperation
for multiple domains
:-(
:-|
Security
:-(
:-[
History
(auto linking)
:-|
Caching /
Facilitation
Mediators
:-(
Abstraction
:-[
:-)
Discovery
|
(
]
Good progress / active research / related work / poor coverage
:-[
:-)
:-)