11.2 Preparing for Deployment

Before you deploy an SOA application, you must plan the deployment process and complete the following tasks:

• Define the requirements for deploying the SOA application

• Configure and set up load balancing within a cluster

• Create data sources (Optional)

• Configure and deploy standalone resource adapters (Optional)

Note: You can create data sources and configure standalone resource adapters after the application has been deployed.

11.2.1 How to Define Deployment Requirements

Before you start using the Application Server Control to deploy your SOA application, ensure that:

• You have already created an application archive (For example, a .ear or .war file). For more information on creating an application archive, refer to the Oracle Containers for J2EE Configuration and Administration Guide.

• You have installed Oracle Application Server 10g Release 3 (10.1.3x) on one or more hosts.

• You have previously logged into the Oracle Enterprise Manager Application Server Control console. For more information, see Section 11.3, "Deploying the Application with Oracle Enterprise Manager Application Server Control".

11.2.2 How to Configure Load Balancing Within a Cluster

The term load balancing refers to the process of distributing incoming service requests over server instances within a cluster. Load balancing in an Oracle Application Server cluster is managed by the mod_oc4j module of Oracle HTTP Server (OHS). In this configuration, the OHS instance acts as a front-end listener for incoming HTTP/HTTPS requests; mod_oc4j then routes each request to an OC4J instance serving the requested application. For more information on load balancing in an Oracle Application Server cluster, refer to Oracle Containers for J2EE Configuration and Administration Guide.

11.2.2.1 OC4J Groups

A group is a loosely synchronized set of like-named OC4J instances that belong to the same cluster topology. Specific configuration options can be executed simultaneously on all OC4J instances in the group.

You can create a group by creating two OC4J instances that have the same name and reside in the same cluster. For example, suppose you install two Oracle Application Server instances and configure them as a cluster. If you create an OC4J instance called home in one instance, and then you create an instance called home in the second instance, a new group called home automatically appears in the Groups section of the Cluster Topology page.

After you create a group, you can perform these common administrative tasks automatically across multiple OC4J instances:

• Process management operations, such as start, stop, or restart

• Deployment operations, such as deploy, undeploy, and redeploy

• JDBC management operations, such as creating, modifying, or removing JDBC data sources and connection pools

• JMS Provider operations, such as creating, modifying, or removing JDBC data sources and connection pools

For more information on managing groups, refer to Oracle Application Server Administrator's Guide.

11.2.2.2 Multiple JVMs

OC4J executes on the Java Virtual Machine (JVM) of the standard Java Development Kit (JDK). By default, each OC4J instance uses one JVM. However, you can configure an OC4J instance so it runs on multiple JVMs.

When you configure an OC4J instance to run on multiple JVMs, the OC4J instance is essentially running on multiple processes. This can improve performance and provide a level of fault tolerance for your deployed applications. However, multiple JVMs also require additional hardware resources to run efficiently.

Note: Application Server Control (represented by the ascontrol application) cannot run on an OC4J instance that is running multiple JVMs. Ensure that you do not configure multiple JVMs on the OC4J instance that is hosting the active ascontrol.

When you run multiple JVMs, consider configuring your deployed application so they take advantage of application clustering. Application clustering ensures that state information is replicated to the different instances of your application running in each JVM.

It is also useful to compare the use of multiple JVMs with the use of application server clusters and groups. For example, when you configure an OC4J instance to run on multiple JVMs, the multiple processes are running on the same host. If the host goes down, all the JVM processes will go down. For more information, see Oracle Containers for J2EE Configuration and Administration Guide.

11.2.2.3 Application Clustering (State Replication)

In addition to clusters and groups, Oracle Application Server 10g Release 3 (10.1.3) introduces the concept of application clustering, which provides state replication and load balancing for applications within your cluster topology.

Within a cluster, you can configure clustering for selected applications that are deployed across the cluster. Application clustering offers the following features:

• You can configure clustering for specific applications or globally by configuring clustering for the default application in an OC4J instance. Other applications deployed to the instance automatically inherit the clustering characteristics of the default application.

• You can configure clustering for an application at deployment time, or later, after you deploy the application.

• You can select from the following replication methods:

  • Peer-to-peer replication

  • Multicast replication

  • Database replication

For more information on application clustering, refer to the Oracle Containers for J2EE Configuration and Administration Guide.

11.2.3 How to Create Data Sources

A data source is a vendor-independent encapsulation of database server connection. A data source instantiates an object that implements the javax.sql.DataSource interface.You can define any type of data source using Oracle Enterprise Manager Application Server Control Console. You can configure and use these data sources in your Oracle Application Server Containers for J2EE (OC4J) application.

Note: You can create the data source after your application has been deployed.

To create data sources and connection pools for a selected OC4 J instance:

1. Navigate to the OC4J Home page for the OC4J instance.

2. Click Administration to display the OC4J Administration page, which contains a table listing the various administration tasks you can perform for this OC4J instance.

3. If necessary, expand the Services section of the table.

4. Click the task icon in the JDBC Resources row of the table to display the JDBC Resources as shown in Figure 11-1.

   Figure 11-1 JDC Resources

   
   Description of "Figure 11-1 JDC Resources"
   
   

5. Click Help for more information about viewing, creating, and deleting data sources and connection pools.

11.2.4 How to Deploy and Configure Standalone Resource Adapters

You can use the Oracle Enterprise Manager Application Server Control console to deploy, monitor, and configure standalone resource adapters, which are packaged and deployed as .rar files. In addition, you can also manage embedded resource adapters, which are deployed as part of an application.

Note: You can deploy and configure standalone resource adapters after the application has been deployed.

Before an application component can use resource adapter connections to an EIS, you must create one or more connection factories. Creating and configuring a connection factory involves the following tasks:

• Identify the connection interface.

• Bind the connection to JNDI.

• Define the connection pooling characteristics.

• Provide any configuration properties for the specific connection factory.

To use the Application Server Control Console to create a new connection factory:

1. Navigate to the Resource Adapter Home page.

2. Click Connection Factories to display the Connection Factories page as shown in Figure 11-2. This page lists the connection factories and shared connection pools defined for the selected resource adapter.

   Figure 11-2 Connection Factories

   
   Description of "Figure 11-2 Connection Factories"
   
   

3. Click Create at the top of the connection factory table and follow the instructions in the Create Connection Factory wizard.

Standalone resource adapters can be deployed just like applications and application modules. Multiple applications can then use a single standalone resource adapter to connect to an enterprise information system (EIS).

To deploy a standalone resource adapter:

1. Navigate to the OC4J Home page for the instance.

2. Click Applications to display the OC4J Applications page.

3. Choose Standalone Resource Adapters from the View drop-down menu to display the Standalone Resource Adapters as shown in Figure 11-3. This page lists the standalone resource adapters that have been deployed to the OC4J instance.

   Figure 11-3 Standalone Resource Adapters

   
   Description of "Figure 11-3 Standalone Resource Adapters"
   
   

4. Click Deploy.

   Follow the instructions in the Deployment wizard. The wizard prompts you for the location of the resource adapter .rar file and prompts you deployment options.