Oracle ,Middle ware technologies,

1. Middleware &
Web Services

2. Purpose of Layered Models
 mask the heterogeneity of systems
 provide convenient programming abstraction

3. Layered Protocols: OSI
Layers, interfaces, and protocols in the OSI model.

4. Middleware Protocols
An adapted reference model for networked communication.

5. Purpose of Middleware
‘Middleware is primarily a set of programming abstractions
developed to facilitate the development of complex
distributed systems.’

6. Middleware provides…
protocols to support general-purpose services to
more specific applications, e.g.
 authentication protocols
 authorization protocols
 distributed commit protocols
 distributed locking protocols
 high-level communication protocols
 remote procedure calls (RPC)
 remote method invocation (RMI)

7. Middleware
1-22
General structure of a distributed system as middleware.

8. Old-style Middleware
programming models
 Remote Calls
 Remote Procedure Calls (RPC)
 Distributed objects and Remote Method Invocation
 E.g. Java RMI
 Common Object Request Broker Architecture (CORBA)
 Cross-language RMI
 Other Programming Models
 Remote event notification
 Remote SQL access
 Distributed transaction processing

9. Message-based Middleware
 Asynchronous
 Sending and receiving documents
 No remote procedure calls or object invocation
 Less coordination required

10. Sources: Middleware
•Adapted from
Introduction to Distributed Systems: Slides for CSCI 3171 Lectures
by E. W. Grundke
•References:
[TvS] A. Tanenbaum and M. van Steen
Distributed Systems: Principles and Paradigms, Prentice-Hall (2002)
<URL:http://www.prenhall.com/divisions/esm/app/author_tanenbaum/custom/dist_sys_1e/>
[CDK] G. Coulouris, J. Dollimore and T. Kindberg
 Distributed System: Concepts and Design, Addison-Wesley (2001)
 <URL:http://www.cdk3.net/ig/beida/>
[ISO] International Organization for Standardization/ International
Electrotechnical Commission
Standard ISO/IEC 7498-1: Information Technology — Open Systems Interconnection — Basic
Reference Model: The Basic Model (Second ed., corrected and reprinted 1996-06-15)
Reference number ISO/IEC 7498-1:1994(E)
 <URL:http://standards.iso.org/ittf/PubliclyAvailableStandards/s020269_ISO_IEC_7498-1_1994(E).zip>

11. Sources: Web Services
 Gustavo Alonso, Fabio Casati, and Harumi Kuno.
 Web Services: Concepts Architectures and Applications (Springer-Verlag, 2004)
 Slides from <URL:http://www.inf.ethz.ch/~alonso/WebServicesBook>.
 Gustavo Alonso and Cesare Pautasso.
 Graduate course given at the University of Lappeenranta,Finland. August 9–13, 2004.
<URL:http://www.inf.ethz.ch/personal/alonso/Web-book/Lappeenranta-graduate-course.zip>