1. Services-based Systems Architecture, Design and Implementation
B.Ramamurthy
11/30/2018

2. Goals “Retrospective” on Project 1 Discussion on plans for Project 2
Lessons learned and pitfalls to avoid
Discussion on plans for Project 2
Artifacts of a large scale distributed system
Architecting a services-based system
Design issues in services-based system
Anything else…
11/30/2018

3. Develop/Deploy(DD) Cycle
Service
Endpoint
Interface
wscompile
Portable
Artifacts
WSDL
Model
wsdeploy
Deployment
Descriptors
Cooked WAR
11/30/2018

4. Invocation Model (client side) or Invoke Cycle
wscompile
Portable
Artifacts
WSDL
Implementation
-specific
Artifacts
Client
Invoke web service
11/30/2018

5. Client Scenarios Service endpoint interface Web service 2 WSDL
JSP
Client
Java App.
Client
Servlet
Client
11/30/2018

6. Artifacts: the server/container
Host with an IP (and ports)
Web servers, servlet servers, application servers
All can be bundled into one
More than one can be installed in a “host” machine at different port (Project 1)
Each has a context root, the path of which represents “/” (Ex: /DBaccess.jsp)
Each has an admin console for managing the server resources such a data source and message queues.
Elegant way to access the resources in a deployed unit is through the container (server).
For java, you will define JNDI (Java Naming and Directory Interface) names for the resources.
Portability of deployable units (Ex: ‘Component technology’: Enterprise Java beans)
11/30/2018

7. Artifacts: the data Relational data base; object relational database
Data modeling (Entity-Relationship modeling)
Tables
Operations
Data access objects (DAO)
Enterprise java beans (EJB)
Enterprise information system (Amazon.com webservices, yahoo feeds)
Legacy systems
Device data (sensors)
RSS, ATOM, XML and text feeds
11/30/2018

8. Artifacts: the services
WS creation for consumption:
Typically create a service from language-dependent interface/class (Ex: Java interface + class)
Generate WSDL for publication and consumption.
WS consumption using a published WSDL.
Generate the language-dependent classes from WSDL
Understand thoroughly the various components of the WSDL: messages, port type, bindings, server (server, port), etc.
11/30/2018

9. Artifacts: the clients
Simple applications to rich client (ex: RIA rich internet application)
Internationalization (languages, monitory units, etc.)
HTTP monitors, cookies and counters
Preference profiles
11/30/2018

10. Plan for Project 2
Commercial strength enterprise application built around web services offered by amazon.com ECS:
Theme: Federation of information from various sources to present an intelligent interface for assembling a system of components in various vertical domains.
Experience is similar to ordering a computer at Dell site.
Examples:
Mundane applications such as furnishing a house for a given budget or without a budget but with preferences. Based on real amazon.com data so that the application can be used by amazon.com customers.
Building a home theater, a music system, stock portfolio, etc.
Interaction models (groups rather than individuals)
Add dynamism to amazon.com experience
Make use of web services you created in Project 2.
Data from other sources such as yahoo feeds.
For persistence you will have oracle data source, CIT data source as well as any local data.
11/30/2018

11. Plan for Project 2 Non-functional requirements:
Reliability (fault handling, exception handling)
Performance (caching, concurrency, thread pooling?)
Elegant data access using data access objects
Validation of any inputs
Junit/Nunit testing
Security authentication
Secure access
Asynchronous operation, push mode
Events, notification, publish, subscribe operations.
Higher level WS-* standards: WS-BPEL, workflow etc.
11/30/2018

12. Project 2: to do
We will explore the features offered by amazon.com and others.
Decide on a project, title, domain, executive summary and project timelines.
Lets look at some demos.
Links: Amazon.com E-Commerce Service (ECS)
Conceptual Model      
ECS Usage/Query Scenarios          
Types of data available through ECS (and not available)
Sample applications (some of them are cool)
11/30/2018