Chapter 9 Portal Server and Application Servers
This appendix provides an overview of Portal Server and its support for application
servers.
This appendix contains the following sections:
Application Server Support in Portal Server
The Portal Server provides support for the following application servers
to be used as the web application container, in addition to the JavaTM Web
Server software:
-
Sun JavaTM SystemApplication Server Enterprise Edition
-
BEA WebLogic ServerTM Server 8.1 SP 2
-
IBM WebSphere® Application
Server 5.1
Note –
Portal Server runs in the context of a web application container, which
can be either a web server or one of the application servers mentioned above, depending
on your deployment.
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 JavaBeansTM architecture and
other J2EETM technologies that run in the application server
container
-
Use application server clustering, which provides scalability
and high availability
-
Use session failover in clustering (currently
available on BEA WebLogic Server andApplication Server Enterprise Edition)
Portal Server on an Application Server Cluster
This section describes how Application Server Enterprise Edition software, BEA
WebLogic Server, and IBM WebSphere® Application
Server manage application server clustering. Application server
clustering is a 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 Access Manager are not pure web applications.
Instead, these applications are composed of local files residing on a machine and
three web applications: portal, amserver, and psconsole. These three web applications
run in a web application container, which runs in an application server web application
container.
The Java Enterprise System 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.
The WAR files 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:
To Install Portal Server on an Application Server
Steps
-
Install Portal Server on all machines using the same configuration settings.
-
Deploy the three web applications (portal, amserver, and psconsole) to
the cluster.
The following sections explain what it means to enable Portal
Server to run on an application server cluster.
Application Server Enterprise Edition
The Sun Java System Application Server Enterprise Edition 8 provides a robust
J2EE platform for the development, deployment, and management of enterprise applications.
Key features include transaction management, performance, scalability, security, and
integration. The Application Server supports services from Web publishing to enterprise-scale
transaction processing.
The Application Server is available in the Platform and Enterprise editions.
The Platform edition is free and is intended for software development and department-level
production environments. Designed for mission-critical services and large-scale production
environments, the Enterprise edition supports horizontal scalability and service continuity
via a load balancer plug-in and cluster management. The Enterprise edition also supports
session continuity via the Highly Available Database (HADB). See the following Application
Server Enterprise Edition documentation for more information:
http://docs.sun.com/db/coll/1310
BEA WebLogic Server
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 Java Enterprise System 2005Q5 Installation Guide 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.
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-306.ibm.com/software/webservers/appserv
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.