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| Sun ONE Portal Server 6.0 Deployment Guide |
Appendix C Sun ONE Portal Server and Application Servers
This appendix provides an overview of Sun™ ONE Portal Server 6.0 and its support for application servers.
This appendix contains the following sections:
- Introduction to Application Server Support in Portal Server
- Portal Server on an Application Server Cluster
For installation and configuration information on the specific application servers supported by Portal Server, see the following documentation:
- Sun ONE Portal Server 6.0 Installation Supplement for Sun ONE Application Server 7.0
- Sun ONE Portal Server 6.0 Installation Supplement for IBM Application Server
- Sun ONE Portal Server 6.0 Installation Supplement for BEA Application Server
Introduction to Application Server Support in Portal Server
The Sun™ ONE Portal Server 6.0 for Multi Application Servers release provides support for the following application servers to be used as the web application container, in place of Sun™ ONE Web Server:
- Sun™ ONE Application Server 7.0
- BEA WebLogic Server 6.1 (SP2)
- IBM WebSphere Application Server 4.04
Running Portal Server on an application server enables you to:
- Decouple the portal platform from the application server platform, allowing you to choose the best combination of Portal Server and application server for your organization
- Call Enterprise JavaBeans™ and other J2EE™ technologies that run in the application server container
- Use application server clustering, which provides scalability and high availability (currently only available on BEA WebLogic Server and IBM WebSphere Application Server)
- Use session failover in clustering (currently only available on BEA WebLogic Server)
Portal Server on an Application Server Cluster
This section describes how Sun ONE Application Server, BEA WebLogic Server, and IBM WebSphere Application Server manage application server clustering. Application server clustering is loosely coupled group of application servers that collaborate to provide shared access to the services that each server hosts. The cluster aims to balance resource requests, high availability of resources, and failover of application logic to provide scalability.
Portal Server and Identity Server are not pure web applications. Instead, they are composed of local files residing on a machine and three web applications: portal, amserver, and amconsole. These three web applications run in a web application container, which runs in an application server web application container. The Portal Server installer installs and configures the local files, configures the local application server, then deploys the three WAR files on the local web application container. The WAR files themselves are not self-contained; they depend on the local files and directories on the machine to provide their service.
An application server cluster is a logical entity that groups many application server instances, potentially hosted on different machines. Pure web applications are deployed on a cluster using application server specific deployment tools. Once deployed on the cluster, the web applications are deployed to all the server instances that the cluster is made of, and managed in a central way.
Because of Portal Server's dual nature, as a local application as well as a web application, install Portal Server on an application server using the following steps:
- Install Portal Server on all machines using the same configuration settings.
- Deploy the three web applications (portal, amserver, and amconsole) to the cluster.
The following sections explain what it means to enable Portal Server to run on an application server cluster.
Overview of Sun ONE Application Server
Sun ONE Application Server 7, Standard Edition Server does not support server clustering or session failover. However, it does support enhanced web tier support by enabling you to partition HTTP and HTTPS traffic arriving on the same web server instance to multiple application servers in the middle tier. This facility in Standard Edition can be used to partition traffic to different application servers from the web server tier by using the provided reverse proxy plugin.
While Platform Edition is limited to a single application server instance (that is, a single JVM™ process) per administrative domain, you can configure the Standard Edition with multiple application server instances per administrative domain.
In addition, the Enterprise Edition supports multi-tiered, multi-machine, clustered application server deployments.
See the following Sun ONE Application Server documentation for more information:
http://docs.sun.com/db/coll/s1_asse_en
Overview of BEA WebLogic Server Clusters
The BEA WebLogic Server product uses the following definitions:
- Domain - An interrelated set of WebLogic Server resources managed as a unit. A domain includes one or more WebLogic Servers, and might include WebLogic Server clusters.
- Administration Server - A WebLogic Server running the Administration Service. The Administration Service provides the central point of control for configuring and monitoring the entire domain. The Administration Server must be running to perform any management operation on that domain.
- Managed Server - In a domain with multiple WebLogic Servers, only one server is the Administration Server; the other servers are called Managed Servers. Each WebLogic Managed Server obtains its configuration at startup from the Administration Server.
See the following documentation for more information:
http://edocs.beasys.com/wls/docs61/cluster/index.html
You start the Administration Server with the following command:
install_dir/config/domain_name/startWeblogic.sh
The local server takes its configuration from the install_dir/config/domain_name/config.xml file. To start a Managed Server, use the following command:
install_dir/config/domain_name/startManagedWebLogic.sh servername admin_server_url
Instead of taking its configuration from the install_dir/config/domain_name/config.xml local file, the Managed Server takes it from the Administration Server, using HTTP.
Note The default configuration supported for installing Portal Server on BEA WebLogic Server is a single server that is also the Administration Server for the domain.
A BEA cluster is a set of managed servers in the same domain, that are declared in the WebLogic console as a cluster. When deploying a web application, you use the name of the cluster, not the name of the individual servers. After the deployment, the web application is identically deployed to all machines in the cluster.
Session failover in BEA is described in the following document:
http://edocs.beasys.com/wls/docs61/cluster/servlet.html#1009453
Using in-memory replication for HTTP session states requires the following prerequisites:
- Portal Server supports the use of WebLogic Server clusters with in-memory session replication. See the BEA documentation for instructions to set up these clusters. The Sun ONE Portal Server 6.0 Installation Supplement for BEA Application Server documents the load balancer configuration for such a cluster using the HttpClusterServlet that ships with BEA. You can also set up other load balancing hardware and software documented by BEA in the same way.
- Session data must be serializable.
- Use the setAttribute to change the session state.
To install a BEA cluster, your BEA license for each machine participating in the cluster must be a special BEA cluster license. See the BEA documentation for the procedure to get the license and set up a BEA cluster with HttpClusterServlet.
Overview of IBM WebSphere Application Server
The IBM WebSphere Application Server product uses the following definitions:
- Administrative domain - The logical space in which the configurations for various objects in the WebSphere environment reside. Inside one administrative domain you start with an application server. This is the default installation.
- Server group - A server group is a template for creating additional, nearly identical copies of an application server configuration. (This is the equivalent of BEA's cluster.)
- Clones - A copy of the server group, on the same machine or on different machines. Clones are the equivalent of BEA's managed servers.
See the IBM WebSphere Application Server documentation for more information:
http://www-3.ibm.com/software/webservers/appserv/doc/v40/ae/infocen ter/was/welcome.html
WebSphere Advanced Server provides a more robust approach to clustering because it includes a database. In Advanced Server, all servers use the database for the configuration information. You can use the WebSphere administration console, a Swing Java™ application, or the command-line utilities XMLConfig and wscpthen to manage the servers.