Enterprise Data Services
for
Strategic SOA
Sumedha Rubasinghe
~ sumedha@wso2.com ~
http://sumedha.blogspot.com

The growth of SOA (Web Services)
• SOA hype
– promises of dynamic discovery
– Human readable messaging
– Simple XML data objects
• SOA approach - finally solving problems
• Application assembly using
– Loosely coupled components
– Well defined interfaces
– Growing demand for mashed up applications
• Interoperability

Enterprise data
• Processed & stored since beginning of
computing era
• Heterogeneous stores
• Generated by application silos
• Disconnected

Concerns
• Each approach demands different way of
access
• Developer time spent on data access

Real world scenarios
• Application A
– Data from one legacy system / data store
• Application B
– Data from two heterogeneous data stores
– Daily Sales Report
• Cash register writes to a flat file
• Product details in a RDBMS

Real world scenarios (continued..)
• Application C - consolidating data from
three data sources
– Datasource 1 : Sales data from a flat file
– Datasource 2 : Inventory data
– Datasource 3 : Sales person data

Ways of solving
• Method 1
– Create a new data store
– Pull relevant data from 3 data stores
– Store it to match Application C’s requirements
– Now comes Application X…
– More overhead
– Redundant data
• Inconsistency
• Update anomalies

Ways of solving (continued..)
• Method 2
– Connect to 3 data sources & extract data
– Three different access mechanisms

Data access mechanisms in SOA
• Direct access to databases
(JDBC,ODBC,..etc)
• Use of O/R mapping frameworks
(Hibernate, Ibatis,...)
• Enterprise Java Beans (EJBs)
• CORBA
• Custom APIs

Method 2
• Issues
– Data access code VS business logic
implementation
– Difficult to reuse
– Difficult to maintain
– Difficult to test
– Error prone

Ways of solving (continued..)
• Method 3
– Single layer to fulfill enterprise data access
requirements
• Governed by,
– More and more data being generated
– Growing demand for consolidated, consistent information
– Mashups
– Interoperability & standards

Positioning of data access code
• Application developers like to deal with
business process related logic
• Changes in data source configuration –
transparent to application logic

Data Service?
• Yet another web service
• Well defined request/response format
• Encapsulates data oriented logic
• Loose coupling (application & data store)
• Data store specific configurations
• Management & QoS features

Challenges - Heterogeneous Data
stores
• RDBMS – specific or generic JDBC drivers
• Directories – specific drivers, API
• Flat files, Spread sheets – different APIs
• Different data types
• Access control mechanisms

Accessing a data service?
• It’s just another web service !!!
– Typical web service call
– REST call
• Direct call to API
<XML> Input Message
Data Services
Solution Database
Output Data
<XML>

Expectations - Data Integration
• Transformation (mediation)
• Federation
• Bridging the gap between
– data structures
– Formats
– Vocabularies
– Data model

Reusability
• It’s a web service
• Create once & use anywhere
• Substantial return down the line

Creation, runtime & management
• Creation
– Web / IDE based wizards
– Simple configuration file
• Runtime
– Start, stop, maintenance mode
– Scalable
– Fault tolerant
• Management
– Versioning, auditing, dynamic modifications

QoS Features
• Security
– Access control
– Content filtering
– Encryption
– Integrity
– WS-Security

QoS Features
• Connection Pooling (RDBMS)
• Caching
• Access Throttling
• High Availability (HA)
• Reliable Delivery
• Notification

QoS Features
• Monitoring & Management
– Audit trails
– Access Logs
– JMX
– Tracing

Advantages of Data Services
• Most up-to-date data using a service call
• Single layer for SOA’s data requirements
• Optimization efforts visible to all
consumers
• Developer productivity
• QoS
• Battle tested runtime

Summary
• Need for Enterprise Data Services for SOA
• Challenges faced when implementing Data
Services
• Defined Data Services
• QoS, Life cycle expectations from a Data
Services implementation

Demo
• Expose Employee contact data in MySQL
database as a service
• Table Structure

Wizard (Step1)

Wizard (Step2)

Wizard (Step3)

WSDL -http://<IP>:<PORT>/services/ContactInfoService?wsdl2

References
• http://wso2.org (Developer Portal for WS
devlopers)
– WSO2 ESB (Apache Synapse)
– WSO2 Web Service Application Server (Apache Axis2)
– Registry
– Mashup Server
– Data Services Solution
– Identity Solution
• http://wso2.org/projects/solutions/data-
services/java
• http://wso2.com(commercial support)

Thank you