How do you establish high availability concepts in the Oracle Application Server

How do you establish high availability concepts in the Oracle Application Server?
High availability is defined by the percentage of time that your server works normally.
You can use hardware cluster for failover to build High availability.
Hardware cluster is a collection of loosely coupled computers where a load balancer
provides a single view of services.
Failover is a process to relocate an application from failed node to a standby node.
You can install as many redundant infrastructures in many servers.
You can install as many J2EE and Web Cache Middle-Tier instance.


How can you create a J2EE and Web Cache Cluster?
Assuming you have two J2EE and web caches installed.
$ORACLE_HOME/webcache1
$ORACLE_HOME/webcache2
Their port assignments are in the
$ORACLE_HOME/webcache(1 or 2)/install/portlist.ini files.
Go to webcache1 to create cluster:
<http://hostname1:4000/> -- log on as the “administrator” userid.
Click Clustering under Properties. In the new page, select the cluster member and
click Edit Selected, enter a new name, submit and restart web cache.
Go to webcache2 to add the web cache to cluster.
Click Clustering under Properties and then click “Add.” Enter information and submit.
In Cache operations, select the new cache cluster and then click Propagate. Then
select all cache and click Restart.