R12 file system has come up with new model – Code, Data, Configurations are segregated nicely to have easy maintenance, to avert NFS mount issues on shared appl tier configuration systems. Auto-config will not write anything in APPL_TOP, COMMON_TOP area in R12. All instance specific configurations, log files are written in INST_TOP area. Instance Home provides the ability to share Applications and technology stack code among multiple instances.
Tech Stack Components
- 10.2.0.2 RDBMS ORACLE_HOME
- 10.1.2 C ORACLE_HOME / FORMS ORACLE_HOME (8.0.6 ORACLE HOME equivalence)
- 10.1.3 Java ORACLE_HOME/OC4J ORACLE_HOME (iAS ORACLE_HOME equivalence)
- INSTANCE_TOP : Each application tier has a unique Instance Home file system associated
Instance home is the top-level directory for an Applications Instance which is known as Instance Home and is denoted the environment variable $INST_TOP. This contains all the config files, log files, SSL certificates etc.
- The additional Instance Home makes the middle tier more easy to manage and organized since the data is kept separate from the config files.
- The Instance Home also has the ability to share the Applications and Technology stack code across multiple instances.
- Another advantage of the Instance Home is that the Autoconfig writes only in INST_TOP so APPL_TOP and ORACLE_HOME can also be made read only file system if required.
- To create a new instance that shares an existing middle-tier, just create a new instance_top with proper config files and NFS Mount the middle tier
$INST_TOP : $APPS_BASE/inst/apps/$CONTEXT_NAME/
/admin /scripts : ADMIN_SCRIPTS_HOME: Find all AD scripts here
/appl : APPL_CONFIG_HOME. For standalone envs, this is set to $APPL_TOP
/fnd/12.0.0/secure : FND_SECURE: dbc files here
/admin : All Env Config files here
/certs : SSL Certificates go here
/logs : LOG_HOME: Central log file location. All log files are placed here (except adconfig)
/ora : ORA_CONFIG_HOME
/10.1.2 : ‘C’ Oracle home config, Contains tnsnames and forms listener servlet config files
/10.1.3 : Apache & OC4J config home, Apache, OC4J and opmn
This is the ‘Java’ oracle home configuration for OPMN, Apache and OC4J
/pids : Apache/Forms server PID files here
/portal : Apache’s DocumentRoot folder