Shared Appl_Top and Shared Application Tier file System

In a traditional oracle apps file system, each node had separate APPL_TOP,COMMON_TOP,apps stack components. With this configuration, if an oracle app patch had to be applied, it need to applied on each node.

In a shared APPL_TOP- APPL_TOP and COMMON_TOP are shared among multiple nodes. Basically, the APPL_TOP and the COMMON_TOP file systems are installed on a shared disk resource which is mounted to each node. However, each node will have separated apps stack component s(IAS_ORACLE_HOME and 8.0.6 ORACLE_HOME)

In a shared Application tier file system-APPL_TOP,COMMON_TOP and Apps tech stack(IAS_ORACLE_HOME  and 8.0.6 ORACLE_HOME) are shared among multiple nodes. So basically,  APPL_TOP,  COMMON_TOP, and the Applications technology stack (ORACLE_HOMEs) are installed on a shared disk resource which is mounted to each node.

Earlier it was shared APPL_TOP and then oracle came out with shared application tier .

All the machines sharing the file system must be configured to run the same Operating System with the same OS patch level. With shared APPL_TOP  and shared application tier file system, oracle apps patch had just to be applied once. However if the patch runs autoconfig (AD patch) then we need to run autoconfig on all the nodes.

Also, on a shared APPL_TOP, if we are applying any patch on 8.0.6 ORACLE_HOME or iAS ORACLE_HOME, then we need to apply it on each application node since the techstack is not shared.

There is a restriction that if you are on Windows, then you CANNOT use shared appl_top/shared application tier.