8 Creating a Session Persistence Module

GlassFish Server enables you to create a session persistence module in the web container for high availability-related functionality by implementing the PersistenceStrategyBuilder interface . Using the PersistenceStrategyBuilder interface in an HK2 service makes the session manager extensible because you can implement a new persistence type without having to modify the web container code.

For information about other high-availability, session persistence solutions, see "Configuring High Availability Session Persistence and Failover" in Oracle GlassFish Server High Availability Administration Guide.

Implementing the PersistenceStrategyBuilder Interface

You can implement the PersistenceStrategyBuilder interface by creating a new web session manager type.

package com.sun.enterprise.web;

import com.sun.enterprise.deployment.runtime.web.SessionManager;
import org.apache.catalina.Context;
import org.jvnet.hk2.annotations.Contract;

@Contract
public interface PersistenceStrategyBuilder {
    
    public void initializePersistenceStrategy(
            Context ctx,
            SessionManager smBean,
            ServerConfigLookup serverConfigLookup);

    public void setPersistenceFrequency(String persistenceFrequency);

    public void setPersistenceScope(String persistenceScope);

    public void setPassedInPersistenceType(String persistenceType);
}

Here is an example of how to implement the PersistenceStrategyBuilder interface by creating a new web session manager and setting a store for it:

@Service(name="xyz")
public class XYZStrategyBuilder implements PersistenceStrategyBuilder {

    private String persistenceFrequency = null;
    private String persistenceScope = null;
    private String persistenceType = null;
 
    public void init(StandardContext ctx, SessionManager sessionManager,
      ServerConfigLookup serverConfigLookup) {
        // add listeners, valves, etc. to the ctx
        // Set the manager and store
    }
 
    public void setPersistenceFrequency(String persistenceFrequency) {
        this.persistenceFrequency = persistenceFrequency;
    }
    
    public void setPersistenceScope(String persistenceScope) {
        this.persistenceScope = persistenceScope;
    }
        
    public void setPassedInPersistenceType(String persistenceType) {
        this.passedInPersistenceType = persistenceType;
    }
}

If a Manager is provided, then it will be used in GlassFish Server.

Note:

If a backing store is required, it is the responsibility of the Manager to make sure that the findSession method correctly uses the Store that the Manager provides.

Example 8-1 Implementing PersistenceStrategyBuilder With a Custom Web Session Manager

This example defines a session manager type that is named MyHASolution.

@Service(name="MyHASolution")
public class MyHASolutionStrategyBuilder implements PersistenceStrategyBuilder {

    private String persistenceFrequency = null;
    private String persistenceScope = null;
    private String persistenceType = null;

    public void init(StandardContext ctx, SessionManager sessionManager,
      ServerConfigLookup serverConfigLookup) {
        // add listeners, valves, etc. to the ctx
        // Set the manager and store
        MyManager myManager = new MyManager(persistenceType, persistenceFrequency); 
        // (You could also make this a service and look it up in the habitat. 
        // For simplicity we are just doing a new implementation of the class here.)
        MyStore store = new MyStore();
        myManager.setStore(store);
        ctx.setManager(myManager);
    }

    public void setPersistenceFrequency(String persistenceFrequency) {
        this.persistenceFrequency = persistenceFrequency;
    }
    
    public void setPersistenceScope(String persistenceScope) {
        this.persistenceScope = persistenceScope;
    }
        
    public void setPassedInPersistenceType(String persistenceType) {
        this.passedInPersistenceType = persistenceType;

    }

} 

Example 8-2 Session Manager Configuration in the glassfish-web.xml File

This example sets the persistence-type attribute of the session-manager element of glassfish-web.xml to myHASolution

Based on the domain.xml and glassfish-web.xml settings, the web container looks up the appropriate PersistenceStrategyBuilder interface in the Habitat and uses it.

       <glassfish-web-app>
         <session-config>
           <session-manager persistence-type="myHASolution"/>
         <session-config>
       <glassfish-web-app>