Oracle B32100-01 - Manual (Page 188)

Setting up the OracleAS Disaster Recovery Environment
10-4 Oracle Application Server Installation Guide
10.2.3 Set Up Identical Hostnames on Both Production and Standby Sites
The names of the corresponding nodes on the production and standby sites must be
identical, so that when you synchronize data between the sites, you do not have to edit
the data to fix the hostnames.
For the Infrastructure Nodes
For the node running the infrastructure, set up a virtual name. To do this, specify an
alias for the node in the /etc/hosts file.
For example, on the infrastructure node on the production site, the following line in
the hosts file sets the alias to asinfra:
138.1.2.111 prodinfra asinfra
On the standby site, the following line sets the node’s alias to asinfra.
213.2.2.110 standbyinfra asinfra
When you install OracleAS Infrastructure on the production and standby sites, you
specify this alias (asinfra) in the Specify Virtual Hostname screen. The configuration
data will then contain this alias for the infrastructure nodes.
For the Middle-Tier Nodes
For the nodes running the middle tiers, you cannot set up aliases like you did for the
infrastructure nodes because the installer does not display the Specify Virtual
Hostname screen for middle-tier installations. When installing middle tiers, the
installer determines the hostname automatically by calling the gethostname() function.
You want to be sure that for each middle-tier node on the production site, the
corresponding node on the standby site returns the same hostname.
To do this, set up a local, or internal, hostname, which could be different from the
public, or external, hostname. You can change the names of the nodes on the standby
site to match the names of the corresponding nodes on the production site, or you can
change the names of the nodes on both production and standby sites to be the same.
This depends on other applications that you might be running on the nodes, and
whether changing the node name will affect those applications.
1. On the nodes whose local names you want to change, reconfigure the node so that
the hostname command returns the new local hostname.
2. Enable the other nodes in the OracleAS Disaster Recovery environment to be able
to resolve the node using the new local hostname. You can do this in one of two
ways:
Method 1: Set up separate internal DNS servers for the production and standby
sites. This configuration allows nodes on each site (production or standby) to
resolve hostnames within the site. Above the internal DNS servers are the
corporate, or external, DNS servers. The internal DNS servers forward
Note: The procedure to change the hostname of a system differs
between different operating systems. Contact the system
administrator of your system to perform this step. Note also that
changing the hostname of a system will affect installed software that
has a dependency on the previous hostname. Consider the impact of
this before changing the hostname.