Shared APPL_TOP in Oracle Apps Basics

Based on lot of request I am discussing on Shared APPL_TOP & Shared Application Tier. For next few days I will start with basics of Shared APPL_TOP like
what’s is Shared APPL_TOP ?
Advantages of Shared APPL_TOP ?
Difference between Shared APPL_TOP & Application Tier
Difference between Shared APPL_TOP & Staged APPL_TOP
How to Implement Shared APPL_TOP in Oracle Apps ?

So rather than talking too much lets start with Shared APPL_TOP & Application Tier .

In order to understand concept of shared APPL_TOP you first need to know what is APPL_TOP & what are various other TOP’s in Oracle Apps .
Oracle Apps File System (Software ) is mainly divided in to five top level directories

DATA_TOP : For data file (Database Tier )
DB_TOP : Database Software 8i, 9i or 10g ( Database Tier )

APPL_TOP : For various product tops (Application Tier )
COMMON_TOP : for files & directories common to all products ( Application Tier )
ORA_TOP : for iAS, Forms & Reports Component , Tech. Stack ( Application Tier )

Why I need shared APPL_TOP ?
If you have two/three (Multiple) Middle Tier for Large User base then you have to install APPL_TOP, COMMON_TOP & ORA_TOP equal to number of Nodes in your configuration. So if you have three middle tier then you need these three top three times & if there are n nodes you need n time these three top’s .
This result in lots of Space Requirement & bigger problem is patching so If you have 5 nodes you need to apply apps patch 5 times.
So Oracle Came Up with solution to have single APPL_TOP which is shared across all nodes in apps. This will save space as well patch timing. This concept of sharing APPL_TOP file system across all Middle Tier Nodes is called as APPL_TOP .
You will say if I can share APPL_TOP why Can’t I share COMMON_TOP & ORA_TOP as well which are also part of Application Tier , Yes you can & this concept is called as Shared Application Tier.

What is Shared Application Tier ?
Sharing Application Tier ( including APPL_TOP, COMN_TOP, ORA_TOP) across all Middle Tier Nodes in configuration is called as Shared Application Tier.

So I can say shared APPL_TOP is subset of shared Application Tier , initially shared APPL_TOP came out & based on its advantages & popularity later COMMON_TOP & ORA_TOP files were also included & entire concept is called as Shared Application Tier.

Limitation with Shared APPL_TOP , Application Tier ?
If you are running Apps on Windows you’ll be sad to hear that its not certified with Windows Operation System. More over you can share across same operation system like Linux to Linux & Solaris to Solaris.

More to come in next post like
Broad Level steps of configure Shared Application Tier ..
difference between Shared Appl_top & staged appl top

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About the Author Atul Kumar

Oracle ACE, Author, Speaker and Founder of K21 Technologies & K21 Academy : Oracle Gold Partner specialising in Design, Implement, and Trainings.

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47 comments
fhasweh says September 21, 2006

can u plz clerafiy the diffrence between Shared Application Tier and Shared Appl_top

fadi

Reply
Atul Kumar says September 21, 2006

Fadi,
as mentioned above, Application Tier Sharing includes sharing APPL_TOP, COMN_TOP, ORA_TOP i.e. whole application tier.

where as shared APPL_TOP means just APPL_TOP file system sharing .

Earlier it was just Shared APPL_TOP which later extended to sharing entire Application Tier.

Atul

Reply
fhasweh says September 22, 2006

thank you atul for reply but still i am not able to understand which is better for me should i go with sharde appl top or sharde file system.

thanks
fadi

Reply
Atul Kumar says September 22, 2006

Fadi,
Looking at your comments, It seems you are not clear with Shared Application Tier funda (No offence to you pls)

shared appl top or shared file system are same thing , you achieve shared appl_top by sharing file system.

If you are talking about shared Appl_Top & shared Application Tier , go for shared Application Tier as this is now a days followed.

Atul

Reply
fhasweh says September 24, 2006

sorry atul,
i was expecting a clerificaiton on both of (shared Appl_Top & shared Application Tier what r the diffreances between them) so i can chose what to follow its not just like go for this or go for that.

keep up the good work
fadi

Reply
Atul Kumar says September 24, 2006

Fadi,
As I mentioned shared APPL_TOP is sharing only APPL_TOP where as in shared Application Tier you share all three application tier tops i.e. APP_TOP, COMN_TOP, ORA_TOP . Earlier apps dba’s were not configuring shared application tier as it was not supported . Now shared application tier is the only option left , you don’t see shared APPL_TOP alone. Though people still call shared application tier as shared APPL_TOP(totally out of ignorance and becoz of similarity in concept).

Atul

Reply
fhasweh says September 25, 2006

atul,
thanks
fadi

Reply
Ravi Bhandari says September 26, 2006

Hi, I am unable to log on via Self service /oa_servlets/Appslogon page after sharing the appl top. I keep getting your session is no longer valid. Have you got a working example of migrating an existing 3 tier system to shared appl top.

Reply
Atul Kumar says September 26, 2006

Ravi,
Which note you followed ?
I suppose some server ID or cookie is not set properly. Can you directly login to forms via dev60cgi/f60cgi ?

Check metalink note
233428.1 Sharing the Application Tier File System in Oracle Applications 11i as mentioned in

Good Metalink Notes

Reply
Anonymous says September 29, 2006

Hi Atul,

Thanks for ur tremendous help
can u plz list the differences between $ORACLE_SID and $TWO_TASK

Thanks,
sudha

Reply
Atul Kumar says September 29, 2006

Sudha,
TWO_TASK mocks your connection descriptor to connect to database More on this at
Whats is TWO_TASK

SID is to identify database Identifier i.e. If SID is set it will try to connect to database locally .

If both SID & TWO_TASK are set , prefence will go to TWO_TASK & it will connect as network using TNS Alais defines as TWO_TASK in tnsnames.ora .

Atul

Reply
Anonymous says October 4, 2006

Can you use ocfs2 for shared file system – I heard gfs stunk

Reply
Anonymous says October 4, 2006

Hi Atul,

What kind of file system is supported for shared APPL_TOP? If we use nfs, does crate a single point failure?

Thanks,

Reply
Atul Kumar says October 4, 2006

Nice Questions,

What kind of file system is supported for shared APPL_TOP?

Any file system which you can mount from to all nodes in shared appl_top is fine.

If we use nfs, does crate a single point failure?
Yes, thats true you are intoroducing single point of failure , here is alternative .

Lets assume you have node1, node2, node3, and node4 .

Create a filesystem share between node1 & node2 and create a snapclone/copy of that file system & mount it across node3 & node4 . After patching represent filesystem from node1,node2 to second file system on node3 & node4 .

That way you can avoid from single point of failure.

Atul

Reply
Atul Kumar says October 4, 2006

baddabingtim,
Yes you can use OCFS2 as well. For others who don’t know about OCFS2 , its Oracle Cluster file system .

This can also be used to configure Standalone Database RAC but its not certified for RAC with Apps.
For RAC with APPS ASM (Automatic Storage Management ) is recommended & certified.

Atul

Reply
Tech_Whiz says November 5, 2006

Atul,

I tried a situation like the following:

I had a shared file system on DB01 and DB02. I created a partition and mounted it on App01 and App02. And In this partition I created a mountpoint /app and I tried to install the APPL_TOP, COMN_TOP and ORA_TOP here…

I had a cluster in DB01 and DB02. Hence I avoided single point of failure as I have NFS mounted in App01 using the virtual name of DB01.

But in such a setup, my Apache was not even getting started. Is there any limitation on using Apache on NFS.

When I went through the httpd.conf there were some highlights when the directive RootDirectory is a shared one… But I couldn’t succeed…

What do you feel about that?

Reply
Atul Kumar says November 6, 2006

Hi Tech whiz,
Which version of apps you are using ?

Did you follow any metalink note ?
If not check if you completed task mentioned in metalink note

233428.1 Sharing the Application Tier File System in Oracle Applications 11i

If even after completing steps in above note then check whats error message in $OAD_TOP/conf/$CONTEXT_NAME/iAS/Apache/Apache/logs

please note your Apache log files changed now from $IAS_ORACLE_HOME/Apache…

to

$OAD_TOP/conf …..or any conf directory you created during shared Appl_top

Now you can raise all these issues in forum dedicated to Apps DBA’s at

http://teachmeoracle.com/forum

Reply
Tech_Whiz says November 7, 2006

Hi Atul,

I very much followed the same Note.

We were with 11.5.10.2 version.

Anyways.. I’ll discuss this in the forum…

Thanks for the great work!!!

Tech Whiz To B!!!

Reply
Rahul says March 20, 2007

Hi Atul,

Can you provide me the steps of installation of Oracle 10g RAC with full structure and in explanation?

Reply
Atul Kumar says March 20, 2007

Rahul,
Check this beautifully written doc on RAC by Jeffrey Hunter

http://www.oracle.com/technology/pub/articles/hunter_rac10gr2_iscsi.html

Reply
vikram says June 13, 2007

Hi Atul,
I want to clarify a dowt reg whether Refresh & Clone are same are not if not what is diffe b/w them.
Vikram

Reply
Atul Kumar says June 13, 2007

Yes, they meant to be same things , creating replica of source instance

Reply
sai says June 15, 2007

How can we monitor the patch progress
in oracle 11i?

Very Good Blog for Apps DBA’s .
Thankyou atul.

Reply
sai says June 15, 2007

How to monitor the patch progress in oracle11i?

Reply
Anonymous says August 8, 2007

Hi Atul,

What happens internally in Shared application file system…like how the forms,web services communicate?

Thanks

Reply
Anonymous says August 13, 2007

Hi Atul

In Shared Application tier configuration, we have been seeing apache crash after generating a core file.

Our server nodes are Solaris Zones and we have 3 web nodes for production database load balances using F5.

Reply
MANN says May 13, 2008

HI ATUL,
I HAVE PROBLEM WITH
This error is coming both for requisition and purchasing.

“APP-PO-14142 GET-PO-PARAMETERS-10:ORA-01403:NODATA FOUND,
SQL ERROR IS ORA-01403:NO DATA FOUND

Thanx mann.

Reply
venugopalt says May 13, 2008

How can I identify whether the instance is in shared APPL_TOP or not?

Reply
Atul says May 13, 2008

login as apps user

SQL>select NODE_NAME,HOST, appltop_id from fnd_nodes where node_name not in (‘AUTHENTICATION’);

Check how many nodes are there and appltop_id are same or not

or

1. Login to one application tier and go to $APPL_TOP then create a text file (touch test.txt)
2. Login to another application tier , go to $APPL_TOP and check if test.txt is visible (If yes then you are on shared appl_top/application tier)

Reply
venugopalt says May 13, 2008

My APPLTOP_ID is blank. What could be the reason?

Reply
venugopalt says May 13, 2008

Hi Atul,

Thanks for the quick response. My APPLTOP_ID is blank. What could be the reason?

Venu

Reply
Aashish says September 15, 2008

Atul

My current OS file system is ext 3 and 2 node application is running. now I want to move on the new servers and want to use shared appltop my question is which OS file system is supported for shared appltop. I don;t want to mount the file system from one server to another as if 1st server will go down then the complete file system is not available for another server. we have SAN storage… now my question is :
1. What OS file system we need to install on SAN to create the SHARED APPL TOP e.g CFS

2. If I copy the application binaries from ext 3 to new shared file system will it be supported or I need to do any additional steps

Reply
» Readers Question - Which Driver (c, d, g, u) to apply on which Node ? Online Apps DBA: One Stop Shop for Apps DBA’s says September 3, 2009

[…] If you are using shared APPL_TOP/Application Tier then run split patch (c,d,g) or unified patch (u) from any one […]

Reply
Sachin says October 9, 2009

Hi Atul
We have Shared application Tier implemented with 2 application node.
To clone from 2 application node to 1 application node (internal filesystem), we will have to execute adpreclone.
1)Do we need to execute on both nodes?
2) Also which ORACLE_HOME and IAS_HOME needs to be copied? do we need to copy from CONFIG_TOP?

Reply
Atul Kumar says October 9, 2009

@ Sachin,

1)Do we need to execute on both nodes?
No, just run it from any one node.

2) Also which ORACLE_HOME and IAS_HOME needs to be copied? do we need to copy from CONFIG_TOP?

I am assuming this is 11i.

Copy ORACLE_HOME (806 and iAS) which contains software.
config_top is not required but if you hit any issues (I am not sure how is your implementation of shared appl_top) then copy source to target.

Reply
latha says September 13, 2010

i want inform… about shared appl_top

Reply
Rafi says February 5, 2011

Hi Atul,

Can you please explain how to change the APPS Password in SHARED APPL_TOP?

Thanx
Rafi

Reply
Atul Kumar says February 5, 2011

@ Rafi,
You use same method of changing password i.e. FNDCPASS on shared appl_top as you do in non shared appl_top.

After changing apps password you have to run autoconfig on all application tier nodes which will update apps password in required locations as required.

Reply
Raffi says February 7, 2011

Thnx Atul……….

Reply
Raffi says February 8, 2011

Hi Atul,
I have one doubt, at the time of run script adcfgclone.pl on DB Tier if it get’s failed then what we hav to do?

Thankyou
Raffi

Reply
Atul Kumar says February 8, 2011

@ Raffi,
Check logs related to adcfgclone and then based on whats reported in logs , fix issue and rerun adcfgclone.pl

For list of log location check

http://onlineappsdba.com/index.php/2007/12/25/oracle-r1212i-log-file-patch-clone-startupshutdown/

Reply
Raffi says February 8, 2011

Hi Atul,
Thnkyou verymuch……

Reply
Raffi says September 20, 2011

Hi Atul,
I have a query related to Linux.
when I used to ZIP command for compressing a 30gb data, it will shows like ‘exceeded’?
what is the problem?
and howmuch memory will be use by ZIP?

Reply
prem reddy says March 10, 2014

How to find out our application system shared appl_top or not?

Reply
    Atul Kumar says March 10, 2014

    @Prem Reddy,

    1. Login to first Server and create file under APPL_TOP
    2. Login to second server and check if you can see file on this APPL_TOP

    If you can see file on second server then you have shared APPL_TOP else not

    Reply
pani says March 27, 2014

How many inst_top will be present in multi application node?

Reply
Gaurav Anand Dwivedi says January 4, 2017

Hi Atul,
What is Middle Tier and Nodes, Why we configure Node? Please elaborate little more. Thanks!

Reply
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