Instance Top in R12

I have briefed R12 architecture in my last post( R12 architecture ). I described that INST_TOP is the most descernible changes that R12 is having from its predecessors. I am going to cover INST_TOP here.

INST TOP directory:

(applmgr) - ls
admin/ appl/ certs/ logs/ ora/ out/ pids/ portal/ rgf/
(applmgr) -

The Whys and wherefores:

You may get a question why is the change??

There is a need to separate


to ease maintenance of the system. To avoid NFS/MUTEX related issues. Above issue will get resolved if the configuration/lcck files are stored in local system. Another advantage is to gain performance accessing local file system is better than NFS file system.

This directory $INST_TOP got introduced newly in R12. Instance top contains all the config files, log files, ssl certificates, document root etc. Addition of this directory makes the middle-tier more organised, since data is kept separate from config/log files. Another advantage is that, multiple instances can easily share the same middle tier. 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 in the server.


ADMIN_SCRIPTS_HOME: Find all AD scripts here
APPL_CONFIG_HOME. For standalone envs, this is set to $APPL_TOP
FND_SECURE: dbc files here
All Env Config files here
SSL Certificates go here
LOG_HOME: Central log file location. All log files are placed here (except adconfig)
'C' Oracle home config, Contains tnsnames and forms listener servlet config files
Apache & OC4J config home, Apache, OC4J and opmn
This is the 'Java' oracle home configuration for OPMN, Apache and OC4J
Apache/Forms server PID files here
Apache's DocumentRoot folder

run autoconfig
stop all services
start all services
start/stop/status Apache only
start/stop/status OC4J Forms
start/stop/status OC4J oacore
start/stop/status opmn
start/stop RPC listeners (FNDFS/FNDSM)
start/stop Concurrent Manager
start/stop FNDSM
start/stop Fulfillment Server
Cloning preparation script to start/stop/status OC4J oafm
(webservice, mapviewer)
Execute sql scripts that update the profiles in an AutoConfig run
Call java executable with additional args, (used by opmn, Conc. Mgr)

Location of various log files
AD Script log files (,...)
AD tools log files (adpatch, ...)
OPMN Log Files (Text & ODL)
Apache Log Files (Text & ODL)
OC4J Log Files (Text)
OC4J Log Files (ODL)

certs is the default directory for SSL or any other certificate files
used by this instance. To use a centrally staged certificate, change
the appropriate context file and run autoconfig

I believe this post helped you lot, stay tuned for next update.


Arunkumar said...

Hey Suresh,
First of all, i would like to thank you for creating this blog for Apps DBAs. This post as compared to others is really descriptive and i have taken a printout of the same for easily navigating to the log and config directories :)

Nice job. I would appreciate if you take steps to cover some of the R12 issues that you face in day-today life. Myself and couple of my friends have started a blog dedicated to Apps DBAs worldwide.

Check out
and do opine.


Anonymous said...

Hi Suresh,

Good Job, one of the best site for R12.


Suresh Lakshmanan said...

Thanks Arun, Kishore


raghu said...


Please tell me where is in r12 i didnt find any where



Suresh Lakshmanan said...

Hi Raghu,

Nope, You wont find jserv component related config files. Jserv is 9i techstack component, it got replaced by 10g Oacore OC4J.


Anonymous said...

HI Suresh,
You have mentioned that jserv has been replaced by oc4j. So what files do we hv to edit to point oc4j to our custom java classes in $XXHR_TOP? We use this instead of the default $JAVA_TOP.

IN 11i, we modified with wrapper.classpath=/a001/DEV/appl/xxhr/11.5.0/java

Thanks in advance

Suresh Lakshmanan said...

Hi A,

Thanks for your comment.
Please mention your name going forward to address you.

You have to change the context XML variable and have to run the auto config. if you need exact xml file where the classpath goes into, i think it is orion_application.xml

let me double check and give you. you may review the article

mail me at suresh.lakshmanan at


Anonymous said...

Thanks for your pointer to the CDATA in the new context files. We tested it with modifying the orion-application.xml directly first and ofcourse that wrked. So then we did it the proper way with changing the contect files.

Suresh Lakshmanan said...

Thanks Aditya. Pleasure helping you out.


Anonymous said...

Hi Suresh,
Thanks for such a nice blog for all Application Dba's. Your efforts are really appreciated.