Sunday, April 12, 2020

Oracle Apps DBA R12.2.x Interview Questions and Answers



 Oracle Apps DBA R12.2.x Interview Questions and Answers


Oracle E-Business Suite R12.2.x Interview Q/A:

1. What is Online Patching?
Ans: Online patching is a new patching mechanism that is available with R12.2 that allows the application of patches while the system is up and running, and the users are working as normal.

2. Which Oracle E-Business Suite releases Online Patching feature is available?
Ans: Online patching is used with Oracle E-Business Suite 12.2 and higher.

3. What types of patch are applied online?
Ans: All Oracle E-Business Suite Release 12.2 patches are applied online. This includes one-off patches, patch rollups, consolidated updates and security patches.

4. What is the Online Patching cycle?
Ans: The Online Patching cycle is a sequence of inter-related steps (phases) used to apply patches to an Oracle E-Business Suite system.

5. What tool is used to apply online patches?
Ans: The AD Online Patching (adop) command-line utility is used to manage the Online Patching cycle.adop invokes adpatch is the background only

6: Is there any downtime in Online Patching?
Ans: There is a short period of downtime when the application tier services are shut down and restarted. The database remains open all the time.

7 Once I upgrade to Release 12.2, can I still apply patches in the traditional way?
Ans: No. All patches for Release 12.2 will be online patches. The traditional, pre-12.2 method of applying patches will not work.There are option like downtime and hotpatch which works more like traditional way but they are used for patches directed by Oracle

8. What is the Online Patching infrastructure?
Ans:This infrastructure includes database objects edition and patch/run file system components.

9. Does Online Patching require the 11gR2 Oracle Database Edition Based Redefinition (EBR) feature?
An: Yes. Online patching depends on the Edition Based Redefinition (EBR) feature that was introduced in the Oracle 11gR2 Database. Most notably, EBR allows editioning of code objects in the database. To do this, it provides new object types such as editions, editioning views, and cross-edition triggers, all of which are part of the Online Patching infrastructure.

10. What are the phases that make up the Online Patching cycle?
Ans: The Online Patching cycle consists of the following phases:
1.Prepare a virtual copy (patch edition) of the running application (run edition).
2.Apply patches to the patch edition of the application.
3.Finalize the system in readiness for the cutover phase.
4.Cutover to the patch edition and make it the new run edition.
5.Cleanup obsolete definitions or data to recover space.

11.What downtime is required during an Online Patching cycle? or as the name spells     online,there is not downtime in the whole process?
Ans: The cutover phase requires a short period of downtime (typically a few minutes) for transition tasks such as a restart of the application tier services.

12. Is any downtime required for the database tier?
Ans: No. In fact, the database needs to be up and running during each phase of the Online Patching cycle. Suite database.

13. How does Online Patching work on the application tier?
Ans: During Release 12.2 installation, Rapid Install will lay down two copies of the application tier file system. One of the copies will be labeled as the run file system, and the other as the patch file system. Subsequently, when a patch is applied, adop will:
1).Synchronize the contents of the run file system to the patch file system. This happens during the prepare phase.
2).Perform patching actions on the patch file system. This happens during the apply phase.
3).Finally, during the cutover phase, the adop utility restarts the application tier services. The patch file system is then promoted to be the new run file system, and the old run file system becomes the patch file system for the next patching cycle.
Note that a third file system, the non-editioned file system (fs_ne), is created to store files containing data that is needed across all file systems,such as log files.

14. How do I apply Oracle Fusion Middle-ware patches in Oracle E-Business Suite Release 12.2?
Ans: During the apply phase of an Online Patching cycle, you apply Oracle Fusion Middle-ware patches to the Oracle homes of the patch edition file system. Then, after the cut over phase is complete, you synchronize the file systems by performing an fs_clone operation. (Also see My Oracle Support Knowledge Document 1355068.1, as listed in Appendix A.)

15. Can I use the patch edition for testing and development purposes?
Ans: As a specialized component of the Online Patching infrastructure, the patch edition is not supported for use as a test environment. You should continue to employ a separate, dedicated test environment.
16.Can Online Patching be used with database technologies such as Active Dataguard and Flashback?
Ans:Yes. Online patching can be used alongside Active Dataguard and Flashback. In fact we can use flashback to rollback the changes after the final cutover

17. What are the key differences between the DBA_OBJECTS, DBA_OBJECTS_AE, and AD_OBJECTS tables?
Ans: DBA_OBJECTS shows object information for the current edition, but the STATUS column in this view may show the object as VALID even if the object actually needs to be compiled before use.
DBA_OBJECTS_AE is similar to DBA_OBJECTS, but shows object information across all editions. This has the drawback of showing objects in old editions that are no longer accessible to the application.
AD_OBJECTS is the Oracle E-Business Suite workaround to the unreliable STATUS column in DBA_OBJECTS. AD_OBJECTS shows the correct status for each object visible in the current edition. It also shows whether the object is “actual” (a real object) in the current edition, or a “stub” object (the object definition was inherited from a previous edition). You can query AD_OBJECTS to locate objects that need to be recompiled before use:
SQL>select owner, object_name, object_type from ad_objects where status = ‘INVALID’
order by 1,2,3
/
The same logic can be applied by running the script:
SQL>sqlplus apps/apps @$AD_TOP/sql/ADZDSHOWINVALID

18. Does Online Patching increase the network port requirements on an Oracle E-Business Suite instance?
Ans: Yes. Online patching requires an additional set of network ports for the Oracle WebLogic Server managed servers on the second file system. During the cutover phase, the managed servers run simultaneously on the patch file system and run file system for a brief period, in a rolling transition process.

19. Is it possible to abort an Online Patching session?
Ans:Yes. Up to cutover, you can run the abort phase to undo the changes made so far in the patching cycle. It is not possible to back out patches once cutover is complete.

20. Is the shared APPL_TOP configuration supported with Online Patching?
Ans: Yes. A shared APPL_TOP configuration is supported and recommended for multi-node application tier implementations in Release 12.2.

21. How does adop work in a multi-node environment?
Ans: The adop Online Patching tool uses remote APIs and ssh login to execute patching operations on remote nodes in a multi-node environment. The node that launches adop becomes the ‘master’ node, and the remote nodes are referred to as ‘slaves’.

22. How do I determine the status of my Online Patching session?
Ans: You can run the adop -status command. This will display information that includes phases completed and the time taken. If you want additional details of operations performed, you can run the adop -status -detail command.

23. What is downtime mode and when can it be used?
Ans: To optimize the process of upgrading to E-Business Suite Release 12.2, the AD Delta 5 Release Update Pack introduced downtime mode, which is used as follows:
$ adop phase=apply patches=<patch_number> apply_mode=downtime
Downtime mode does not use an online patching cycle. The process of applying a patch in downtime mode completes more quickly than in online mode, but at the cost of increased system downtime.
When applying Oracle E-Business Suite patches in this mode, adop will first confirm that the application tier services are down, and will then proceed to apply the patch to the run edition of the Oracle E-Business Suite database and file system.
Downtime mode is supported for:
-All patching (including post-upgrade patching) that forms part of the Release 12.2 upgrade process and is completed before the system is scaled up, the application tier services are started, and users log in to the upgraded system.
-Single-node development or test environments, where production support and high availability are not required.
Downtime mode allows the 12.2 upgrade process to be completed as quickly as possible. Once the upgrade is complete and users are online, all subsequent patching on a production system should use online mode, not downtime mode, unless the patch readme states otherwise.
Several restrictions apply to the use of downtime mode:
-You cannot validate successful patch application before cutover to the updated code takes place.
-There is no capability to abort a failed patch and return to the existing run edition.
-Release 12.2 patches are not normally tested in downtime mode.
-Use of downtime mode in a multi-node application tier environment is not tested or supported.

24. What can I do to reduce the time required for cutover?
Ans: It is important to distinguish between the time needed for the whole cutover phase, and the downtime period within the phase. The actual downtime (during which users cannot log in) is significantly shorter than the whole phase. To help reduce the overall time taken by cutover, you can do three things:
-Run the finalize phase explicitly, to obviate the need for cut over to do so.
-Shut down the concurrent managers before running cut over, to avoid having to wait for concurrent requests to complete. Alternatively, ensure no long-running concurrent jobs are submitted while a patching cycle is in progress.
-Ensure you are using the maximum number of parallel workers your system will support.

25. What is fs_clone and how is it used?
Ans: The command adop phase=fs_clone is a special command that is used to copy the run file system to the patch file system. Also see previous question.

26. Will AutoConfig and adadmin maintenance tasks such as adrelink,forms compilation,report compilation be performed online?
Ans: Yes, these maintenance tasks will be performed online. The relevant operations will be targeted to the patch file system, and should be performed during a patching cycle. They will not have any impact on the run file system.

27. Does Online Patching change the way data fix patches are applied to Oracle E-Business Suite 12.2?
Ans: Yes. Data fix patches (used to fix transactional data) require special handling. The patch readme will give full instructions.

28. How do I apply or patch my customizations in Oracle E-Business Suite Release 12.2?
Ans: You should apply your customizations to the patch edition during the apply phase of the Online Patching cycle. Because this happens prior to the cutover phase, your changes will be propagated to the new run edition (along with all the fixes in the patches applied during the patching cycle).

29. If custom code is installed on a separate database schema, do I have to edition-enable my custom database schema?

Ans: The coding standards in the Oracle E-Business Suite Developer’s Guide state that the first step to any custom application development is to register the custom Oracle schema with the Oracle E-Business Suite applications. The Online Patching enablement patch enables edition on all the schemas registered with the application. If you follow this process, your schema will be edition-enabled automatically.

30. Are there any special considerations for creating custom patches that are compliant with Online Patching?
Ans: Yes. There are some special considerations for creating custom patches that are compliant with Online Patching. Refer to the Patching Standards section of Oracle E-Business Suite Developer’s Guide.

31: How is a non Oracle E-Business Suite database schema able to access the Oracle E-Business Suite tables?
Ans: Any third-party schema, either from third-party products or custom code, must access Oracle E-Business Suite tables via the synonyms in the APPS schema. Direct access to Oracle E-Business Suite tables may produce incorrect results.

32: What are the main technological difference between R12.2 and R12.1
Ans: R12.2 uses weblogic while R12.1 uses OC4J. Apart from that we have online patching feature in r12.2 using edition and patch/run file system

33: How to change the apps password in R12.2?
Ans: apps password is same as R12.1 with the exception of changing that in weblogic console also.

34: where are the log files stored for adop?
Ans: It is stored in the third filesystem which is non edition filesystem

35. how do you connect to the patch edition?
Ans: Source the env using patch option
/u71/R122/EBSapps.env patch

36: How to determine the web logic version in R12.2
Ans: After Logging into the application set the environment to RUN Filesystem
. /u01/oracle/R122/EBSapps.env run
Then, cat $FMW_HOME/wlserver_10.3/.product.properties | grep WLS_PRODUCT_VERSION
You will get Below Output:
WLS_PRODUCT_VERSION=10.3.6.0
To find the FMW version Oracle E-Business Suite Component Version on R12.2
$export ORACLE_HOME=/u01/oracle/R122/fs1/FMW_Home/Oracle_EBS-app1
./opatch lsinv
You will get below Output
Oracle E-Business Suite Component 11.1.1.6.0
Addidtion Info

********************************************************************
Oracle WebLogic Server 10.3.6 in Oracle Fusion Middleware 11g Release 1 (11.1.1.6)
Oracle Fusion Middleware
10.3.6 WebLogic Server (WLS)
11.1.1.6 OHS (WebTier)

37. How to add and delete the manage node in R12.2?
Ans:  I was working on R12.2 Test env and I was supposed to decrease the JVM for the oacore(delete the manage server)
The procedure to increase or decrease JVM was quite simple in R12.1.X.  In Oracle E-Business Suite Release 12, the oacore, oafm, forms and forms-c4ws services were deployed as applications on OC4J instances and were managed by Oracle Process Manager (OPMN).So we just need to increase the numprocs in opmn.xml  and start the services or run autoconfig with decrease numprocs in Context file
I came to know it is quite different in R12.2.X as  Oracle WebLogic Server has replaced OC4J in Oracle E-Business Suite Release 12.2, these services are now deployed as applications on individual managed servers.
Only part of the configuration of these applications and managed servers is still managed via AutoConfig.Rest of things need to done quite different
I have already explained on how to add manage server in my previous post
How to add the manage server in R12.2
In the below, I would be explaining what I learned from that experience and How to delete the manage server in R12.2.  I will particularly taking the example of oacore
Steps on How to delete the manage server in R12.2
Deletion of managed servers needs to be done on the run file system when there is no active ADOP cycle. During the next adop prepare, the Configuration Change Detector identifies that the addition has been made and the managed servers are automatically synced up from the run file system to the patch file system. The synchronization also gets done when fs_clone is executed.
2. If the managed server to be deleted is running, shut it down as follows:
On UNIX:
$ sh <ADMIN_SCRIPTS_HOME>/admanagedsrvctl.sh stop <MANAGED SERVER NAME>
For example, before deleting a managed server ‘oacore_server2’, execute the following command to shut it down.$ sh <ADMIN_SCRIPTS_HOME>/admanagedsrvctl.sh stop oacore_server2
3. Run the command below on the application tier node where the managed server resides. This will delete the managed server, and also update the respective context variables that contain references to the deleted managed server.
$ perl <AD_TOP>/patch/115/bin/adProvisionEBS.pl \
ebs-delete-managedserver \
-contextfile=<CONTEXT_FILE> -managedsrvname=<MANAGED_SERVER_NAME> \
-servicetype=<SERVICE_TYPE> -logfile=<LOGFILE>
For example, for deleting a managed server ‘oacore_server2’ of type ‘oacore’, execute the following command:$ perl <AD_TOP>/patch/115/bin/adProvisionEBS.pl \
ebs-delete-managedserver \
-contextfile=<CONTEXT_FILE> -managedsrvname=oacore_server2 \
-servicetype=oacore -logfile=<APPLRGF>/TXK/delMS_oacoreserver2.log
4. Perform the following steps on all application tier nodes participating in the same cluster as the deleted managed server:
(a) Source the run file system.
(b) If the deleted managed server is part of the cluster configuration defined on the current node, execute the following command to delete details of the managed server from the OHS configuration files mod_wl_ohs.conf and apps.conf on the current node:
$ perl <FND_TOP>/patch/115/bin/txkSetAppsConf.pl \
-contextfile=<CONTEXT_FILE> \
-configoption=removeMS \
-oacore=<host>.<domain>:<port> \
-oafm=<host>.<domain>:<port> \
-forms=<host>.<domain>:<port> \
-formsc4ws=<host>.<domain>:<port> \
-ekanban=<host>.<domain>:<port> \
-accessgate=<host>.<domain>:<port> \
-yms=<host>.<domain>:<port>where¦The argument contextfile accepts the complete path to the context file.
¦The arguments oacore, oafm, forms, formsc4ws, ekanban, accessgate and yms accept a comma-separated list of managed server details in the following format:
<host>.<domain>:<port> ¦host, domain and port are the hostname, domain and port of the managed server whose reference is to be deleted.
For example, to remove references of the deleted managed server oacore_server2 with port 9705 on host ‘myserver’ and domain ‘go.com’, the following command should be executed:
$ perl <FND_TOP>/patch/115/bin/txkSetAppsConf.pl -contextfile=<CONTEXT_FILE> \
-configoption=removeMS -oacore=myserver.go.com:9705
3. If Oracle HTTP Server is enabled on the node, restart it as follows:
On UNIX:
$ sh <ADMIN_SCRIPTS_HOME>/adapcctl.sh stop
$ sh <ADMIN_SCRIPTS_HOME>/adapcctl.sh start
As I told earliar ,the steps are very different from R12.1.X  in R12.2.X.

38. Where are the log file located in R12.2 Apache and Weblogic?
Ans: Apache Logs

$IAS_ORACLE_HOME/instances/*/diagnostics/logs/OHS/EBS_web_*/*log
OPMN Log
$IAS_ORACLE_HOME/instances/*/diagnostics/logs/OPMN/opmn/*
Weblogic Logs
$IAS_ORACLE_HOME/../wlserver_10.3/common/nodemanager $EBS_DOMAIN_HOME/servers/oa*/logs/*
$EBS_DOMAIN_HOME/servers/forms*/logs/*
$EBS_DOMAIN_HOME/servers/AdminServer/logs/*
$EBS_DOMAIN_HOME/sysman/log/*

39. How to stop and start the services in R12.2
Ans: When we want to stop all application services using script adstpall.sh , we provide apps password in R12.1.3.But in R12.2 it will ask weblogic admin password in addition to bring down to all services .
We need to provide Weblogic admin password

Component                                                             Command
Node Manager                                       $adnodemgrctl.sh start Enter Weblogic Admin Password:
Weblogic Admin Server                               $adadminsrvctl.sh start Enter Weblogic Admin Password:
Application Listener                               $adalnctl.sh start
Oracle Process Manager                                $adopmnctl.sh start
Apache Services                                       $adapcctl.sh start
Managed Server for OACORE Services     $admanagedsrvctl.sh start oacore_server1 Enter Weblogic Admin Password:
Managed Server for FormsServices      $admanagedsrvctl.sh start forms_server1 Enter Weblogic Admin Password:
Managed Server for Fusion MiddleWare  Services $admanagedsrvctl.sh start oafm_server1 Enter Weblogic Admin Password:
Managed Server for Forms web  Services $admanagedsrvctl.sh start forms-c4ws_server1 EnterWeblogic Admin Password:
Concurrent Manager Service                        $adcmctl.sh start apps/apps
Fullfillment Serer Services                         $jtffmctl.sh start


40. Do we need to copy the Oracle fusion middleware in R12.2 cloning?
Ans: It is not required in R12.2 cloning as adpreclone copies the Oracle fusion middle in compressed format on the application tier

41.  What is domain in Web Logic?
Ans: Domain is logical grouping of resources and services and consist of Administration Server, Managed Server and cluster.  There can only be one administration Server in domain and zero to N Managed Server.

Note: Before creating domains let us understand Domain, Administration Server, Managed Server and Cluster in Oracle Web Logic. How to create basic Domain (Administration Server only) and Domain with Managed Server Cluster (one Administration Server and two Managed Server in cluster) using Configuration Manager.

42. What is Administration Server?
Ans: Administration Server is WebLogic Server instance that maintains configuration data for a domain. You can deploy your application on administration Server but it is recommended to create managed Server and deploy your application in managed server and leave Administration domain for configuration and maintenance.
—There will always be at least one Administration Server in a domain.
43. What is Managed Server?
Ans: Any WebLogic Server instance apart from Administration Server is called as Managed Servers. This is weblogic server where you deploy your application (Though you can deploy your application in Administration server as well but it is not recommended in production/UAT instance)

44. What is Cluster in WebLogic ?
Ans: Group of WebLogic Managed Server Instances that work together to provide high availability and scalability for applications is called cluster. WebLogic Servers with in cluster can run on same machine or different machines. These are also called as managed Server cluster.

45. Things you should know before creating domain in WebLogic Server ?
Ans: You use configuration wizard to create or extend domain but this can be used only in offline mode (when weblogic server is not running)
— You can also use WLST (WebLogic Scripting Tool), command line tool to create and extend domains in WebLogic Server.
— You can also use unpack command to create new domain. This command can’t be used to extend domain.
— Extending a domain means, you already created domain and now wish to extend it (use more application, add managed server, create cluster…)
— Configuration wizard can be run in Graphical Mode (interactive GUI) or Console Mode (interactive text based)
— For silent mode use WLST (WebLogic Scripting Tool)
— While creating domain you specify Startup Mode (Development or Production). In development mode, you get autodeploy option and security is low. In production mode you need username/password to deploy applications.
— When you create domain, it creates following directories
i) autodeploy ii) bin iii) config (config.xml for domain sits here)  iv) console-ext v) lib vi) security vii) servers
–You use config.cmd (windows) or config.sh (unix) from $BEA_HOME/ wlserver_<ver>/ common/ bin to start configuration manager to create domain
- Below Flowchart (image from Oracle Documentation) displays steps to create domain.

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