Author: Apps DBA

How to Restore context file in oracle applications?

Scenario: Your Applications context file is either accidentally deleted or Corrupted. You do not have any latest backup of context file available.

Below are the steps to recreate context file 

The Applications context file can be retrieved by running the adclonectx.pl script.

perl /clone/bin/adclonectx.pl retrieve

Above script prompts for Database connection Info, apps username/password , Available Context files and the location to which context files can be restored.When prompted for the context file to be retrieved, select the option of retrieving the Applications tier context file that has been lost and retrieve it to the default location as in $CONTEXT_FILE parameter.

The above command can be used only when INST_TOP the is still intact. Incase if INST_TOP is also lost, the Applications tier context file may be retrieved as follows:

Execute the following command on the Database tier:
perl /appsutil/clone/bin/adclonectx.pl retrieve

When prompted for the context file to be retrieved, select the option of retrieving the Applications tier context file that has been lost.Choose the location to any writeable location and copy the restored context file to the value specified in $CONTEXT_FILE parameter on Application Tier.

To retrieve the Database tier context file,

Execute the following command on the Database tier:
perl /appsutil/clone/bin/adclonectx.pl retrieve

When prompted for the context file to be retrieved, select the Database tier context file and retrieve it to the default location ($CONTEXT_FILE on DB node).




Oracle Applications R12.2.5 New Features: dualfs in cloning


From Oracle Applications Release 12.2.5 Version, we have dualfs option for cloning applications tier.We can use this feature in earlier 12.2.x versions also, if AD-TXK Delta 7 patch is applied.Before AD-TXK Delta 7, it was required to run adcfgclone twice on run and patch filesystems.Using dualfs option,we can create both run and patch fs at one time.



-bash$ perl adcfgclone.pl appsTier dualfs


                     Copyright (c) 2002, 2015 Oracle Corporation
                        Redwood Shores, California, USA


                        Oracle E-Business Suite Rapid Clone


                                 Version 12.2


                      adcfgclone Version 120.63.12020000.56


Enter the APPS password :


Enter the Weblogic AdminServer password :


Do you want to add a node (yes/no) [no] :




Running: Context clone…


Log file located at /u01/VISN/fs1/EBSapps/comn/clone/bin/CloneContext_1023194859.log


Provide the values required for creation of the new APPL_TOP Context file.


Target System Hostname (virtual or normal) [appsmt] :


Target System Database SID : VISN


Target System Database Server Node [r12erpt] : appsdb


Target System Database Domain Name [domain.com] :


Target System Base Directory : /u01/VISN


Target System Base Directory set to /u01/VISN


Target System Current File System Base set to /u01/VISN/fs1


Target System Other File System Base set to /u01/VISN/fs2


Target System Fusion Middleware Home set to /u01/VISN/fs1/FMW_Home
Target System Other File System Fusion Middleware Home set to /u01/VISN/fs2/FMW_Home


Target System Web Oracle Home set to /u01/VISN/fs1/FMW_Home/webtier
Target System Other File System Web Oracle Home set to /u01/VISN/fs2/FMW_Home/webtier


Target System Appl TOP set to /u01/VISN/fs1/EBSapps/appl
Target System Other File System Appl TOP set to /u01/VISN/fs2/EBSapps/appl


Target System COMMON TOP set to /u01/VISN/fs1/EBSapps/comn
Target System Other File System COMMON TOP set to /u01/VISN/fs2/EBSapps/comn


Target System Instance Home Directory [V] : /u01/VISN


Target System Current File System Instance Top set to /u01/VISN/fs1/inst/apps/VISN_appsmt


Do you want to preserve the Display [appsmt:0.0] (y/n)  : n


Target System Display [r12erpt:0.0] : appsmt:3.0


Target System Root Service [enabled] :


Target System Web Entry Point Services [enabled] :


Target System Web Application Services [enabled] :


Target System Batch Processing Services [enabled] :


Target System Other Services [disabled] :




Do you want the target system to have the same port values as the source system (y/n) [y] ? : n


Target System Port Pool [0-99] : 88


Checking the port pool 88
done: Port Pool 88 is free
Report file located at /u01/VISN/fs1/inst/apps/VISN_appsmt/admin/out/portpool.lst


UTL_FILE_DIR on database tier consists of the following directories.


1. /usr/tmp
2. /usr/tmp
3./u01/VISN/product/12.1.0/appsutil/outbound/VISN_appsmt
4. /usr/tmp
Choose a value which will be set as APPLPTMP value on the target node [1] : 3
The new APPL_TOP context file has been created :
  /u01/VISN/fs1/inst/apps/VISN_appsmt/appl/admin/VISN_appsmt.xml
Check Clone Context logfile /u01/VISN/fs1/EBSapps/comn/clone/bin/CloneContext_1023194859.log for details.


Creating Patch file system context file…..


Log file located at /u01/VISN/fs1/EBSapps/comn/clone/bin/CloneContextPatch_1023194973.log


Target System Other File System Instance Top set to /u01/VISN/fs2/inst/apps/VISN_appsmt


Target System Port Pool [0-99] : 89


Checking the port pool 89
done: Port Pool 89 is free
Report file located at /u01/VISN/fs2/inst/apps/VISN_appsmt/admin/out/portpool.lst
The new APPL_TOP context file has been created :
 /u01/VISN/fs2/inst/apps/VISN_appsmt/appl/admin/VISN_appsmt.xml
Check Clone Context logfile /u01/VISN/fs1/EBSapps/comn/clone/bin/CloneContextPatch_********.log for details.


FMW Pre-requisite check log file location : /u01/VISN/fs1/EBSapps/comn/clone/FMW/logs/prereqcheck.log
Running: FMW pre-req check…


Configuring: Run file system….
LogFile located at /u01/VISN/fs1/inst/apps/VISN_appsmt/admin/log/clone/run/RCloneApplyAppstier_*******.log

What are the differences between Oracle Applications R12.1.x and R12.2.x

From DBA perspective, below are the changes in R12.2.x version of Oracle Applications, compared to R12.1.3.



1. Dual FS: Oracle Application Release 12.2 has dual filesystems(RUN FS and PATCH FS) to facilitate Online Patching.This Requires double the mountpoint space at MiddleTier Level.


2. Weblogic Server: Oracle HTTP Server in R12.1 is replaced by Oracle Weblogic Server.
10.1.3 Home is replaced by FMW_HOME.Weblogic Server Manages all oacore, forms and oafm servers in R12.2.

3. Online Patching : Dual Filesystem and EBR feature in 11gR2 Database facilitate online patching. Online Patching minimizes the downtime required for patching.adpatch utility in R12.1.x is replaced by adop utility. adop cycle runs in 5 Phases : prepare,apply,finalize,cutover and cleanup. adop internally calls adpatch utility to run the driver files associated with adop phases.

4. APPS Password Change: After Changing Apps Password in R12.2, we need to update the new password in EBS Datasource used by Weblogic Domain.To know more about apps password change in Oracle applications R12.2, check the below link.


5. Cloning : While Cloning of R12.2.x adcfgclone instance needs to be run twice,  on RUN fs and PATCH fs.From 12.2.5 Version (OR R12.AD-TXK Delta 7), we have the dualfs option which creates both run fs and patch fs during clone process.

How to Configure RMAN Backups into Multiple Locations?

If we need  RMAN to distribute backup sets among multiple disks on different mountpoints. We can use the below syntax to configure backup in multiple locations.

Using Allocate Channel:

RUN
{
ALLOCATE CHANNEL c1 DEVICE TYPE DISK FORMAT ‘/u01/oracle/data1’; 
ALLOCATE CHANNEL c2 DEVICE TYPE DISK FORMAT ‘/u02/oracle/data2’; 
}

Using Configure Channel:

CONFIGURE CHANNEL DEVICE TYPE DISK FORMAT ‘/u01/%U’, ‘/u02/%U’;


Oracle RMAN (Recovery Manager) Concepts

What is the difference between obsolete and expired Backup in RMAN?

Obsolete Backup: Backup pieces or backup sets which are not needed for recovery.
We can use the REPORT OBSOLETE command to list the obsolete backups and DELETE OBSOLETE command to delete the obsolete backup.

Expired Backup:When the CROSSCHECK command is used to determine whether backups recorded in the repository still exist on disk or tape, if RMAN cannot locate the backups, then it updates their records in the RMAN repository to EXPIRED status.We can then use the DELETE EXPIRED command to remove records of expired backups from the RMAN repository.


Oracle DBA Concepts: Background Processes in Oracle ASM (Automatic storage Management)

The following background processes are an integral part of Automatic Storage Management:


ARBn performs the actual rebalance data extent movements in an Automatic Storage Management instance. There can be many of these processes running at a time, named ARB0, ARB1, and so on.


ASMB runs in a database instance that is using an ASM disk group. ASMB communicates with the ASM instance, managing storage and providing statistics. ASMB can also run in the ASM instance. ASMB runs in ASM instances when the ASMCMD cp command runs or when the database instance first starts if the SPFILE is stored in ASM.


GMON maintains disk membership in ASM disk groups.


MARK marks ASM allocation units as stale following a missed write to an offline disk. This essentially tracks which extents require resync for offline disks.


RBAL runs in both database and ASM instances. In the database instance, it does a global open of ASM disks. In an ASM instance, it also coordinates rebalance activity for disk groups.


How to change Rebalance Power in ASM Instances?

Whenever a new diskgroup is added or dropped, ASM automatically performs REBALANCING operation.Power used by rebalacing defaults to value specified for asm_power_limit initialization parameter.We can check the status of rebalancing from v$asm_operation view.

Increasing the value of ASM_POWER_LIMIT, reduces the estimated time for completion of Rebalance Operation.

ASM power limit can be increased using the below command

alter system set asm_power_limit =11;

To know more about values for this parameter, check this link:

http://www.appsdbadiaries.com/2017/06/asm-features-rebalancing.html


But this does not increase the rebalancing power of current operation. 

To increase the rebalancing power of ongoing operation, use the below command

 alter diskgroup dg1 rebalance power 11;

We can also specify rebalance power at the time of adding or dropping disks.

alter diskgroup dg1 add disk d01 rebalance power 11;


When to use asm_power_limit 0?

Whenever there is a need to add/drop several disks (like migrations), setting the power limit to 0 is highly beneficial.We can avoid the waiting time for rebalance operation to complete,before the next disk is rebalanced.In such cases, set the asm_power_limit to 0, add/drop all the disks and set the value of asm_power_limit to a non zero value.
Rebalance operation will be parallelized and completes faster.


Oracle Database ASM Features: REBALANCING

ASM has the ability to rebalance data across the disks whenever a disk is added,dropped or replaced.
The performance of rebalance operation is controlled by initialization parameter ASM_POWER_LIMIT.


ASM_POWER_LIMIT Parameter


Default value 1


Range of Values 0 to 11 (Prior to 11gR2)


Range of Values 0 to 1024(From 11gR2)


For 10g Databases:


SQL> alter diskgroup DG1 rebalance power 12;
alter diskgroup DG1 rebalance power 12
                                              *
ERROR at line 1:
ORA-15102: invalid POWER expression


SQL> alter diskgroup DG1 rebalance power 11;


Diskgroup altered.




For 11g AND 12c Databases


SQL> alter diskgroup DG1 rebalance power 1025;
alter diskgroup DG1 rebalance power 1025
                                      *
ERROR at line 1:
ORA-15102: invalid POWER expression


SQL> alter diskgroup DG1 rebalance power 1024;


Diskgroup altered.


The higher the value of rebalancing power, faster would be rebalancing operation.