Supporting Multi-tenancy Applications with Java EE Rodrigo Cândido da Silva @rcandidosilva JavaOne 2014 CON4959

About Me • Brazilian guy ;) • Work for Integritas company

•  http://integritastech.com

• Software Architect •  Java Platform

•  JUG Leader of GUJavaSC •  http://gujavasc.org

•  Twitter •  @rcandidosilva

• Personal •  http://rodrigocandido.me

Agenda • Cloud Services Model • SaaS Market • Multi-tenancy

•  Challenges •  Pros and Cons •  Strategy Types

•  Java EE + Multi-tenancy • Multi-tenancy at Cloud

Cloud Services Model

SaaS Market

Multi-tenancy • One application instance to multiple clients (tenant)

•  Inverse of the multiple instances architecture

Multi-instances vs. Multi-tenant

Multi-instances vs. Multi-tenant Feature Multi-instances Multi-tenant Cost Structure Can support only tiered or

flat pricing Supports usage based pricing as well as tiered or flat

Resources Dedicated resources Shared resources Operation and Maintenance

Manage and administer as many instances as customers

Manager and administer a single instance for a number of customers

Scalable Model Not scalable. As the number of customers increase the maintenance requirements increase proporcionally

Scalable, since a number of customers are serviced by one instance

Cloud != Multi-tenancy

Challenges • Data separation • UI and business rules customization • Access control by tenant • Resource provisioning •  Integration • Application update • Failover tolerance

Pros and Cons • Pros

•  Low maintenance cost •  Same source code for all customers

•  High scalability •  Sharing resources between customers

• Cons •  High complexity

•  Separation by tenant-id •  More failure risks

•  If code breaks -> breaks to all customers •  Low flexibility available to the customers

Multi-tenancy • Adoption levels

•  Level 1 (Customized) •  [N] applications and [N] databases

•  Level 2 (Configurable) •  [1] application and [N] databases

•  Level 3 (Scalable) •  [1] application and [1] database

Level 1 - Customized •  [N] applications and [N] databases

Level 2 - Configurable •  [1] application and [N] databases

Level 3 - Scalable •  [1] application and [1] database

What is the Best Choice? • Depends on…

• Data Customization •  Addition or removal of columns in the data store

•  Function Customization •  The functionality executed for a specific business can vary by

customers

• Process Customization •  The business process can vary for each customer

•  Licensing Features •  The product has multiple licenses which define the functionality

that is enabled for the customer

Database Strategy Separate Databases

Separate Tables

Shared Database

Database Strategy Feature Separate DBs Separate Tables Shared Database Data Customization Security Inter-dependency and Performance Scalable Model Customer On-boarding

Java EE + Multi-tenancy • Database

•  JPA + Multi-tenancy

• UI Customization •  JSF + Multi-tenancy

•  Java EE 8 with Cloud support

JPA + Multi-tenancy •  There is no standard at this time • EclipseLink

•  Multi-tenancy support using @Multitenant •  Multitenant strategies

•  @Multitenant(SINGLE_TABLE) – default •  @Multitenant(TABLE_PER_TENANT) •  @Multitenant(VPD)

• Hibernate •  Supports tenant identifier features

•  MultiTenantConnectionProvider •  CurrentTenantIdentifierResolver

EclipseLink SINGLE_TABLE @Entity @Table(name=“EMP”) @Multitenant(SINGLE_TABLE) @TenantDiscriminatorColumn(name = “TENANT_ID”, contextProperty = “tenant-id”) public class Employee { ... }

HashMap properties = new HashMap(); properties.put("tenant.id", "707"); ... EntityManager em = Persistence .createEntityManagerFactory( "multi-tenant”,properties) .createEntityManager();

<persistence-unit name="multi-tenant"> ... <properties> <property name="tenant.id" value="707"/> ... </properties> </persistence-unit>

EclipseLink TABLE_PER_TENANT <entity class="Employee"> <multitenant type="TABLE_PER_TENANT"> <tenant-table-discriminator type="SCHEMA" context-property="eclipselink.tenant-id"/> </multitenant> <table name="EMP"> ... </entity>

@Entity @Table(name=“EMP”) @Multitenant(TABLE_PER_TENANT) @TenantTableDiscriminator(type=SCHEMA, contextProperty="eclipselink.tenant-id") public class Employee { ... }

EclipseLink VPD

@Entity @Multitenant @TenantDiscriminatorColumn(name = "USER_ID", contextProperty = "tenant.id") @Cacheable(false) public class Task implements Serializable { ...

CALL DBMS_RLS.ADD_POLICY ('SCOTT', 'TASK', 'todo_list_policy', 'SCOTT', 'ident_func', 'select, update, delete'));

<properties> <property name="eclipselink.session.customizer" value="example.VPDSessionCustomizer" /> <property name="eclipselink.session-event-listener" value="example.VPDSessionEventAdapter" /> <property name="eclipselink.jdbc.exclusive-connection.mode" value="Always" /> </properties>

Hibernate MultiTenantConnectionProvider

public class MultiTenantProvider

implements MultiTenantConnectionProvider {

public Connection getConnection(String tenantIdentifier) throws SQLException {

final Connection connection = getAnyConnection();

connection.createStatement().execute(

"SET SCHEMA '" + tenantIdentifier + "'"); return connection;

}

public void releaseConnection(String tenantIdentifier, Connection connection) throws SQLException {

releaseAnyConnection(connection);

}

}

Hibernate CurrentTenantIdentifierResolver public class SchemaResolver implements

CurrentTenantIdentifierResolver { @Override public String resolveCurrentTenantIdentifier() {

return resolveTenant(); } @Override public boolean validateExistingCurrentSessions() {

return false; } }

Hibernate persistence.xml <?xml version="1.0" encoding="UTF-8"?> <persistence version="2.0" xmlns="http://java.sun.com/xml/ns/ persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http:// java.sun.com/xml/ns/persistence/persistence_2_0.xsd"> <persistence-unit name="default"> <properties> <property name="javax.persistence.provider"

value="org.hibernate.ejb.HibernatePersistence" />

<property name="hibernate.multiTenancy" value="SCHEMA"/> <property name="hibernate.tenant_identifier_resolver" value="yourpackage.SchemaResolver"/> <property name="hibernate.multi_tenant_connection_provider" value="yourpackage.MultiTenantProvider"/>

</properties> </persistence-unit> </persistence>

JPA Caching • Shared Cache disabled

JPA Caching • Shared Cache by tenant

JSF + Multi-tenancy •  Flexible software architecture • Artifacts packaged in separated JAR’s • Composition at runtime •  Templates and contracts • Resource library •  Look-and-feel customization • RenderKit features •  Localization support

JSF Facelets

The Facelets Gazette

SiteNavigation

●Events

●Docs

●Forums

About Contact Site Map

Template File name _template.html

Insertion points

Resourcescss classes, scripts, images

JSF Multi-templating • Resource Library Contracts

•  Convention •  All available contracts discovered at startup

•  Configuration •  faces-config.xml by <resource-library-contract> •  contracts attribute in <f:view>

contractA

• Declared Templates• Declared Insertion Points• Declared Resources

contractB

• Declared Templates• Declared Insertion Points• Declared Resources

contractC

• Declared Templates• Declared Insertion Points• Declared Resources

<web-app-root>/contractscontractD

• Declared Templates• Declared Insertion Points• Declared Resources

contractE

• Declared Templates• Declared Insertion Points• Declared Resources

contractF

• Declared Templates• Declared Insertion Points• Declared Resources

JAR files in WEB-INF/lib

JSF Multi-templating

contractA

• Declared Templates• Declared Insertion Points• Declared Resources

contractB

• Declared Templates• Declared Insertion Points• Declared Resources

contractC

• Declared Templates• Declared Insertion Points• Declared Resources

<web-app-root>/contractscontractD

• Declared Templates• Declared Insertion Points• Declared Resources

contractE

• Declared Templates• Declared Insertion Points• Declared Resources

contractF

• Declared Templates• Declared Insertion Points• Declared Resources

JAR files in WEB-INF/lib

Set of available contracts

Facelet 1<f:view contracts="contractA">

...

Facelet 3Facelet 2

faces-config.xml

JSF Multi-templating <html xmlns="http://www.w3.org/1999/xhtml” xmlns:h="http://java.sun.com/jsf/html” xmlns:ui="http://java.sun.com/jsf/facelets"> <body> <ui:composition template="#{template}”> ... </ui:composition> </body> </html>

<?xml version="1.0" encoding="UTF-8"?> <web-app> <context-param> <param-name>javax.faces.view.TEMPLATE</param-name> <param-value>mybusiness</param-value> </context-param> </web-app>

Demo • EclipseLink MySports Demo

•  http://wiki.eclipse.org/EclipseLink/Examples/MySports •  http://git.eclipse.org/c/eclipselink/examples.git

Questions

?

References •  http://msdn.microsoft.com/en-us/library/aa479086.aspx •  https://developers.google.com/appengine/docs/java/multitenancy/ •  http://www.ibm.com/developerworks/java/library/j-multitenant-java/index.html •  http://www.eclipse.org/eclipselink/documentation/2.4/jpa/extensions/a_multitenant.htm •  http://2012.con-fess.com/sessions/-/details/122/JSF-and-JavaEE-7-for-multi-tenant-

applications •  http://jdevelopment.nl/jsf-22/ •  http://picketlink.org •  https://developers.google.com/appengine/docs/java/multitenancy/ •  http://www.jboss.org/quickstarts/picketlink/picketlink-authentication-idm-multi-tenancy/ •  http://wiki.eclipse.org/EclipseLink/Examples/MySports

Thank you! @rcandidosilva

rodrigocandido.me