OSGi Community Event 2013 (http://www.osgi.org/CommunityEvent2013/Schedule) Lightning Talk ABSTRACT This Lightning talk shows an example how to use use an EclipseLink composite Persistence Unit in an OSGi Bundle to seamless combine a Relational Database and NoSQL MongoDB. Furthermore it gives some best practice how to use a JPA Persistence Unit with Blueprint.

1. Polyglot Persistence with
OSGi
Combining relational databases
and NoSQL MongoDB with
EclipseLink
OSGi Community Event
Ludwigsburg
Eclipsecon 2013
Alexander Grzesik

2. Polyglot Persistence
http://martinfowler.com/bliki/PolyglotPersistence.html

3. EclipseLink composite persistence unit
Since 2.3
NoSQL
SQL
From: http://wiki.eclipse.org/EclipseLink/Examples/JPA/Composite
Eclipsecon 2013
Polyglot Persistence with OSGi

4. SQL Persistence Unit
• Plain JPA PU jar
• PU‘s must use same transaction strategy
<persistence-unit name="persistence-test-sql"
transaction-type="RESOURCE_LOCAL">
<non-jta-data-source>jdbc/test</non-jta-data-source>
• Class Mappings
<class>medisite.eclipsecon.entities.sql.BMIUser</class>
• Member PU setting
<property name="eclipselink.composite-unit.member"
value="true"/>
• PU specific settings
<property name="eclipselink.target-database"
value="POSTGRESQL"/>
…
Eclipsecon 2013
Polyglot Persistence with OSGi

5. NoSQL Persistence Unit
• EclipseLink NoSQL support for
– MongoDB
– OracleNoSQL
• Configure like SQL PU
<persistence-unit name="persistence-test-nosql"
transaction-type="RESOURCE_LOCAL">
<class>medisite.eclipsecon.entities.nosql.BMIRecord</class>
…
<property name="eclipselink.composite-unit.member"
value="true"/>
Eclipsecon 2013
Polyglot Persistence with OSGi

6. MongoDB Configuration
• Tell the PU it uses MongoDB
<property name="eclipselink.target-database"
value="org.eclipse.persistence.nosql.adapters.mongo.
MongoPlatform"/>
<property name="eclipselink.nosql.connection-spec"
value="org.eclipse.persistence.nosql.adapters.mongo.
MongoConnectionSpec"/>
• Configure Connection
<property name="eclipselink.nosql.property.mongo.host"
value="localhost"/>
<property name="eclipselink.nosql.property.mongo.port“
value="27017"/>
<property name="eclipselink.nosql.property.mongo.db“
value="test"/>
Eclipsecon 2013
Polyglot Persistence with OSGi

7. Mapping NoSQL Entities
• Add @NoSQL Annotation
@Entity
@NoSql(dataFormat = DataFormatType.MAPPED)
public class BMIRecord {
@Basic
private String name;
@ElementCollection
private List<BMIResult> bmiResults;
@OneToOne()
private BMIUser user;
• Embeded entity
@Embeddable
@NoSql(dataFormat = DataFormatType.MAPPED)
public class BMIResult {
…
Eclipsecon 2013
Polyglot Persistence with OSGi

8. Composite Persistence Unit
• Defines visible PU name
<persistence-unit name="persistence-composite" transactiontype="RESOURCE_LOCAL">
• Included Member PUs
<jar-file>medisite.eclipsecon.pu-nosql-0.0.1.jar</jar-file>
<jar-file>medisite.eclipsecon.pu-sql-0.0.1.jar</jar-file>
• Composite PU setting
<property name="eclipselink.composite-unit" value="true"/>
• Settings for all PUs
<property name="eclipselink.logging.level" value="FINEST"/>
<property name="eclipselink.target-server" value="SunAS9"/>
Eclipsecon 2013
Polyglot Persistence with OSGi

9. Composite PU MANIFEST:
Embedded-Artifacts:
medisite.eclipsecon.pu-sql-0.0.1.jar,
medisite.eclipsecon.pu-nosql-0.0.1.jar
Export-Package:
medisite.eclipsecon.entities.sql;uses:="javax.persistence";versi
on="0.0.1",
medisite.eclipsecon.entities.nosql;
uses:="org.eclipse.persistence.nosql.annotations,javax.persisten
ce,medisite.eclipsecon.entities.sql";version="0.0.1"
Import-Package:
javax.persistence;version="[2.1,3)",
org.eclipse.persistence.jpa;version="[2.5,3)",
org.eclipse.persistence.nosql.adapters.mongo;version="[2.5,3)",
org.eclipse.persistence.nosql.annotations;version="[2.5,3)",
org.eclipse.persistence.platform.server.sunas;version="[2.5,3)",
com.mongodb,…
JPA-PersistenceUnits: persistence-test
Meta-Persistence: META-INF/persistence.xml
Eclipsecon 2013
Polyglot Persistence with OSGi

10. Summary
• No JTA transactions
• No referential integrity between DBs
• Not all Eclipselink features are supported:
Persistence Unit Properties for Composite Pus
• Transparent combination of different databases
• Use JPA API
• Works as OSGi persistence bundle
• Blueprint integration via Aries JPA
Eclipsecon 2013
Polyglot Persistence with OSGi

11. Further Information
• http://wiki.eclipse.org/EclipseLink/UserGui
de/JPA/Advanced_JPA_Development/Co
mposite_Persistence_Units
• http://wiki.eclipse.org/EclipseLink/Example
s/PolyglotPersistence
• Contact me:
mailto:alexander.grzesik@medisite.de
Eclipsecon 2013
Polyglot Persistence with OSGi

12. Questions ?
More on OSGi, Persistence and Cloud:
Tomorrow 11:15
TRESOR: The modular cloud - Building a domain specific
cloud platform with OSGi
Eclipsecon 2013
Polyglot Persistence with OSGi