1 2 Previous Next 15 Replies Latest reply: Dec 12, 2012 9:44 PM by 819737 RSS

    Simulate Failover between Primary RAC to single instance

    819737
      Hi Expert,

      How can i simulate Failover test between Primary RAC instance to single instance running on 11gr2 with both ASM running. Please someone can provide me the correct step to simulate. This is my first experience conduct test on Production server to DR server. I have configure dataguard broker in between.

      Regard
      William
        • 1. Re: Simulate Failover between Primary RAC to single instance
          CKPT
          816734 wrote:
          Hi Expert,

          How can i simulate Failover test between Primary RAC instance to single instance running on 11gr2 with both ASM running. Please someone can provide me the correct step to simulate. This is my first experience conduct test on Production server to DR server. I have configure dataguard broker in between.

          Regard
          William
          William,
          Some confusion on terminology.

          failover in terms of RAC -- Users can be connect to one node and any time they can failover to other surviving nodes of the cluster, In this case no interaction with standby database

          Switchover -- Roles will be changed from Primary to standby and vice versa,

          Failover -- You will perform failover, when there is no primary/production database available because of any crash/disaster.

          Probably you are looking for switchover? can you please read above three differences and describe us more about your requirement.

          Note:- File system doesnt matter if you perform either switchover or failover.


          Using Broker you can manage very simple and easy. Some examples:-
          DGMGRL> switchover to 'db_unique_name';
          DGMGRL> failover to 'db_unique_name';

          Hope this helps.
          • 2. Re: Simulate Failover between Primary RAC to single instance
            819737
            Hi.

            Thanks for the feedback. Actually i request by managment to test FAILOVER TO dr server when our primary RAC db was totally fail to recover . I need to test Failover to DR server using dgmgrl. Can you provide me some example

            Regard
            William
            • 3. Re: Simulate Failover between Primary RAC to single instance
              CKPT
              816734 wrote:
              Hi.

              Thanks for the feedback. Actually i request by managment to test FAILOVER TO dr server when our primary RAC db was totally fail to recover . I need to test Failover to DR server using dgmgrl. Can you provide me some example

              Regard
              William
              In this case you have to forget of your Primary RAC. :)

              To perform failover from Broker use the commands
              1) Connect to the standby database using Oracle Net service with broker DGMGRL
              2) DGMGRL> FAILOVER TO "DB_UNIQUE_NAME";

              http://docs.oracle.com/cd/B19306_01/server.102/b14230/cli.htm#i1007698
              http://docs.oracle.com/cd/B28359_01/server.111/b28295/sofo.htm#CHDDIEAC
              • 4. Re: Simulate Failover between Primary RAC to single instance
                819737
                Hi expertise,

                I need some experience people verify my step as per below by using dgmgrl for failover test. My primary RAC db call nios1 and nios2 and my single DR server is niosdr. Hope someone can give me advise for simulation

                STEP - connect from primary RA db

                1. Disable automatic restart in Primary RAC db - srvctl disable database -d nios

                2. ps -ef | grep pmon | grep -v grep - Kill pmon id on both nios1 and nios2


                3. dgmgrl > show configuration

                4. dgmgrl > failover to 'NIOSDR'


                Regard
                liang
                • 5. Re: Simulate Failover between Primary RAC to single instance
                  CKPT
                  816734 wrote:
                  Hi expertise,

                  I need some experience people verify my step as per below by using dgmgrl for failover test. My primary RAC db call nios1 and nios2 and my single DR server is niosdr. Hope someone can give me advise for simulation

                  STEP - connect from primary RA db

                  1. Disable automatic restart in Primary RAC db - srvctl disable database -d nios

                  2. ps -ef | grep pmon | grep -v grep - Kill pmon id on both nios1 and nios2


                  3. dgmgrl > show configuration

                  4. dgmgrl > failover to 'NIOSDR'


                  Regard
                  liang
                  These steps are depend on the availability of your RAC primary. Lets suppose whole cluster is not accessible, do you think you can execute "SRVCTL" commands?
                  and the second step you have mentioned to kill the mandatory background processes, If database is available and facing with unresolvable issues then you can perform shutdown instead of killing sessions.
                  And i want to say one thing, when there is no database accessible, Why you want to check 1,2 steps?
                  Even step 3 is not helpful to you because the configuration status will be No Success, of course you can just check what are the databases are part of the broker configuration. So in such cases you can directly perform step 4.

                  If you want to perform DR test, You no need to kill the sessions, Just defer the connection between primary and standby ensure no sessions are connected. and straight away perform failover of standby database from standby too.
                  • 6. Re: Simulate Failover between Primary RAC to single instance
                    819737
                    Hi,

                    Thanks for the update. Can i just using srvctl stop database -d nios on primary RAC for shutdown database on primary db and straight go to DR server run dgmgrl > failover to 'NIOSDR' for simulate the test. There is not need to kill any backgroup processes. We asume that the primary db still accessible and all the log has been apply to standby db.

                    Regard
                    William
                    • 7. Re: Simulate Failover between Primary RAC to single instance
                      CKPT
                      816734 wrote:
                      Hi,

                      Thanks for the update. Can i just using srvctl stop database -d nios on primary RAC for shutdown database on primary db and straight go to DR server run dgmgrl > failover to 'NIOSDR' for simulate the test. There is not need to kill any backgroup processes. We asume that the primary db still accessible and all the log has been apply to standby db.

                      Regard
                      William
                      If you would like to keep your primary as active, until you perform failover the primary database keep sending data to the standby database. Once you perform failover the new incarnation will be started and the standby role will be changed to primary role and no more redo will be received or applied. of course once you perform failover either you can stop the database or even you can disable from the configuration. That is what you looking for?

                      Thanks.
                      • 8. Re: Simulate Failover between Primary RAC to single instance
                        819737
                        Hi,

                        Thank for the update. This is what i looking for if the primary still available for access without issue. If i fail over to my standby db (NIOSDR) and old primary will need to restore back right ?? I can use reinstate ??

                        Regard
                        William
                        • 9. Re: Simulate Failover between Primary RAC to single instance
                          CKPT
                          816734 wrote:
                          Hi,

                          Thank for the update. This is what i looking for if the primary still available for access without issue. If i fail over to my standby db (NIOSDR) and old primary will need to restore back right ?? I can use reinstate ??

                          Regard
                          William
                          No need to restore. You can use reinstate, ensure flashback is enabled. Refer link http://docs.oracle.com/cd/E11882_01/server.112/e17023/cli.htm#BGBBDEBC
                          DGMGRL> reinstate database 'db_unique_name';
                          • 10. Re: Simulate Failover between Primary RAC to single instance
                            819737
                            Hi Guru,


                            What happen if i perform dgmgrl > switchover to niosdr -> dr server . After sucessfully switch role, then issue dgmgrl > failover to 'NIOS' ->primary db . Do we still need to perform anything ?? This scenario is assume that both primary db and DR server is accessible without issue.



                            Regard
                            William
                            • 11. Re: Simulate Failover between Primary RAC to single instance
                              CKPT
                              What happen if i perform dgmgrl > switchover to niosdr -> dr server . After sucessfully switch role, then issue dgmgrl > failover to 'NIOS' ->primary db .
                              1) If you perform switchover, then niosdr will become new primary database and nios becomes as new standby database
                              2) you can perform failover only on Standby database, after successful switchover the standby database is nios , So from nios you have to perform failover as DGMGRL> failover to nios; Then database nios will be changed as primary role.
                              Do we still need to perform anything ?? This scenario is assume that both primary db and DR server is accessible without issue.
                              After performing above role transition, Still you willl have two primary databases nios and niosdr , Then again you have to reinstate the database to covert it to standby role.

                              Hope this clears.
                              • 12. Re: Simulate Failover between Primary RAC to single instance
                                819737
                                Hi Guru,

                                Thanks for your explanation. To perform dgmgrl > failover to nios, this need to login on primary rac and run dgmgrl or standby database ??
                                As you mention we have two primary database nios and niosdr, so we need to reinstate niosdr to become standby role. It is correct. what is the step


                                Regard
                                liang
                                • 13. Re: Simulate Failover between Primary RAC to single instance
                                  CKPT
                                  Thanks for your explanation. To perform dgmgrl > failover to nios, this need to login on primary rac and run dgmgrl or standby database ??
                                  Issue the "Failover to nios" from the target standby database you want to change to the primary role.
                                  As you mention we have two primary database nios and niosdr, so we need to reinstate niosdr to become standby role. It is correct. what is the step
                                  Broker performs failed primary database as standby database, Perform the below steps

                                  1) Perform clean shutdown and start in mount status
                                  2) Connect to the new primary database.
                                  3) from DGMGRL use reinstate command.
                                  After successful transition, the database will become as a standby database to the new primary database

                                  Hope this helps.
                                  • 14. Re: Simulate Failover between Primary RAC to single instance
                                    819737
                                    Hi Guru,

                                    I still bit confuse. From step 3, the new primary database is niosdr or nios. From step 4, reinstated which unique db name.

                                    Regard
                                    William
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