Design Considerations 3-21
fulfilled. The modification of the TTL is effectively modifying the caching semantics of the address resolution from a long period of time to a short period. Due to the
shortened caching period, an increase in DNS requests can be observed.
3.2 Storage Considerations
This section provides recommendations for designing storage for the Disaster Recovery solution for your enterprise deployment.
3.2.1 Oracle Fusion Middleware Artifacts
The Oracle Fusion Middleware components in a given environment are usually interdependent on each other, so it is important to have the components in the
topology be in sync. This is an important consideration for designing volumes and consistency groups. Some of the artifacts are static while others are dynamic.
Static Artifacts Static artifacts are files and directories are that do not change frequently. These
include:
■
MW_HOME: The Oracle Middleware home usually consists of an Oracle home and an Oracle WebLogic Server home.
■
Oracle Inventory: The oraInst.loc and oratab files, which are located in the etc directory.
■
BEA Home List: On UNIX, this is located at user_homebeabeahomelist.
Dynamic or Run-Time Artifacts Dynamic or run-time artifacts are files that change frequently. Run-time artifacts
include:
■
Domain Home: Domain directories of the Administration Server and the Managed Servers.
■
Oracle Instances: Oracle Instance home directories.
■
Application artifacts, such as .ear or .war files.
■
Database artifacts such as the MDS repository.
■
Database metadata repositories used by Oracle Fusion Middleware.
■
Persistent stores, such as JMS Providers and transaction logs.
3.2.2 Oracle Home and Oracle Inventory
Oracle Fusion Middleware allows creating multiple Managed Servers from one single binary installation. This allows the installation of binaries in a single location on a
shared storage and the reuse of this installation by the servers in different nodes. However, for maximum availability, Oracle recommends using redundant binary
installations.
When an ORACLE_HOME or a WL_HOME is shared by multiple servers in different nodes, it is recommended to keep the Oracle Inventory and Middleware home list in
those nodes updated for consistency in the installations and application of patches.
To update the oraInventory in a node and attach an installation in a shared storage to it, use ORACLE_HOMEouibinattachHome.sh.
3-22 Oracle Fusion Middleware Disaster Recovery Guide
To update the Middleware home list to add or remove a WL_HOME, edit the user_ home
beabeahomelist file. This would be required for any nodes installed additionally to the ones shown in this topology.
3.2.3 Storage Replication
