Sunday 4 December 2011

Sharing the Application Tier File System

A traditional multi-node installation of Release 11i required each application tier to maintain its own file system, consisting of the APPL_TOP file system (APPL_TOP, COMMON_TOP, and a few related directories) and the application tier technology stack file system (8.0.6 ORACLE_HOME and iAS ORACLE_HOME). Subsequently, this was modified to allow the APPL_TOP to be shared across machines, and later to enable sharing of the entire application tier file system.
Continuing this strategy, Rapid Install for Release 12 creates a system that shares not only the APPL_TOP and COMMON_TOP file systems, but the application node technology stack file system as well. Rapid Install sets up this configuration as the default for nodes that are running the same operating system. These files make up the application tier file system, and can be shared across multiple application tier nodes (provided they are running the same operating system).
Note: A shared file system configuration is currently not supported on application tier server nodes running Windows.
With a shared application tier file system, all application tier files are installed on a single shared disk resource that is mounted from each application tier node. Any application tier node can then be used to provide standard services, such a serving forms or Web pages, or concurrent processing.
Figure 2-8 Shared Application Tier File System
the picture is described in the document text
As well as reducing disk space needed, there are several other benefits of a shared application tier configuration:
  • Most administration, patching, and maintenance tasks need be performed only once, on a single application tier node
  • Changes made to the shared file system are immediately accessible on all application tier nodes
  • Distributes processing tasks to run in parallel on multiple nodes (Distributed AD)
  • Reduces overall disk requirements
  • Makes adding additional application tier nodes easier

Sharing the Application Tier File System Between Instances

Capabilities for sharing the application tier file system were extended further in Release 12.0.4, which introduced the option of sharing an existing Oracle E-Business Release 12 file system with another database instance. An application tier file system installed and configured in this way can be used to access two (or more) database instances.
Restrictions on this are:
  • All database instances must be patched to the same level.
  • Only the application tier file system can be shared, not the database tier file system.
Note: For further details of features, options, and implementation steps, see My Oracle Support Knowledge Document 384248.1, Sharing the Application Tier File System in Oracle E-Business Suite Release 12.

No comments: