1 2 Previous Next 17 Replies Latest reply on Jun 30, 2017 2:05 AM by Hemant K Chitale

    DGMGRL - FSFO Configuration with Maximum Performance Mode

    CloudDB

      Hi Oracle Gurus,

       

      Our Environment:

      Oracle12c 2-Node Grid/RAC with ASM on RHEL Platform

       

      Exiting Database Deployment:

      RAC to RAC Active Data guard

       

      Solution we are looking for:

      We want to configure Data guard - Data broker FSFO with Maximum Performance Mode.

      We don't want to configure Flashback database on primary or standby.

      We don't want to reinstate automatically.

       

      DGMGRL> show configuration

      Configuration - DGConfig

       

        Protection Mode: MaxPerformance

        Members:

        blrdb - Primary database

          blrdr - Physical standby database

       

      Fast-Start Failover: DISABLED

       

      Configuration Status:

      SUCCESS   (status updated 44 seconds ago)

      DGMGRL> show fast_start failover;

      Fast-Start Failover: DISABLED

       

        Threshold:          60 seconds

        Target:             (none)

        Observer:           csm-srv-130

        Lag Limit:          10 seconds

        Shutdown Primary:   TRUE

        Auto-reinstate:     TRUE

        Observer Reconnect: (none)

        Observer Override:  FALSE

       

      Configurable Failover Conditions

        Health Conditions:

          Corrupted Controlfile          YES

          Corrupted Dictionary           YES

          Inaccessible Logfile            NO

          Stuck Archiver                  NO

          Datafile Offline               YES

       

        Oracle Error Conditions:

          (n

      one)

       

      DGMGRL> show configuration verbose

      Configuration - DGConfig

       

        Protection Mode: MaxPerformance

        Members:

        blrdb - Primary database

          blrdr - Physical standby database

       

        Properties:

          FastStartFailoverThreshold      = '60'

          OperationTimeout                = '30'

          TraceLevel                      = 'SUPPORT'

          FastStartFailoverLagLimit       = '30'

          CommunicationTimeout            = '180'

          ObserverReconnect               = '0'

          FastStartFailoverAutoReinstate  = 'TRUE'

          FastStartFailoverPmyShutdown    = 'TRUE'

          BystandersFollowRoleChange      = 'ALL'

          ObserverOverride                = 'FALSE'

          ExternalDestination1            = ''

          ExternalDestination2            = ''

          PrimaryLostWriteAction          = 'CONTINUE'

       

      Fast-Start Failover: DISABLED

       

      Configuration Status:

      SUCCESS

      DGMGRL> enable fast_start failover;

      Error: ORA-16693: requirements not met for enabling fast-start failover

       

      Regards,

      Hitgon

        • 1. Re: DGMGRL - FSFO Configuration with Maximum Performance Mode
          Dejan T.

          Ensure that the standby database you choose to be the target of fast-start failover has its LogXptMode property set to SYNC.

          Please, copy/paste the output of these commands:

           

          dgmgrl> show database verbose blrdb;
          dgmgrl> show database verbose blrdr;
          
          • 2. Re: DGMGRL - FSFO Configuration with Maximum Performance Mode
            CloudDB

            DGMGRL> show database verbose blrdb;

             

            Database - blrdb

             

              Role:              PRIMARY

              Intended State:    TRANSPORT-ON

              Instance(s):

                blrdb1

                blrdb2

             

              Properties:

                DGConnectIdentifier            = 'blrdb'

                ObserverConnectIdentifier      = ''

                LogXptMode                      = 'ASYNC'

                RedoRoutes                      = ''

                DelayMins                      = '0'

                Binding                        = 'optional'

                MaxFailure                      = '0'

                MaxConnections                  = '1'

                ReopenSecs                      = '300'

                NetTimeout                      = '30'

                RedoCompression                = 'DISABLE'

                LogShipping                    = 'ON'

                PreferredApplyInstance          = ''

                ApplyInstanceTimeout            = '0'

                ApplyLagThreshold              = '0'

                TransportLagThreshold          = '0'

                TransportDisconnectedThreshold  = '30'

                ApplyParallel                  = 'AUTO'

                StandbyFileManagement          = 'AUTO'

                ArchiveLagTarget                = '0'

                LogArchiveMaxProcesses          = '5'

                LogArchiveMinSucceedDest        = '1'

                DbFileNameConvert              = '+DATA, +ORADATA'

                LogFileNameConvert              = '+DATA, +ORADATA'

                FastStartFailoverTarget        = 'blrdr'

                InconsistentProperties          = '(monitor)'

                InconsistentLogXptProps        = '(monitor)'

                SendQEntries                    = '(monitor)'

                LogXptStatus                    = '(monitor)'

                RecvQEntries                    = '(monitor)'

                StaticConnectIdentifier(*)

                StandbyArchiveLocation(*)

                AlternateLocation(*)

                LogArchiveTrace(*)

                LogArchiveFormat(*)

                TopWaitEvents(*)

                (*) - Please check specific instance for the property value

             

            Database Status:

            SUCCESS

             

            DGMGRL> show database verbose blrdr;

            Database - blrdr

             

              Role:              PHYSICAL STANDBY

              Intended State:    APPLY-ON

              Transport Lag:      0 seconds (computed 0 seconds ago)

              Apply Lag:          0 seconds (computed 1 second ago)

              Average Apply Rate: 27.00 KByte/s

              Active Apply Rate:  1.06 MByte/s

              Maximum Apply Rate: 25.05 MByte/s

              Real Time Query:    ON

              Instance(s):

                blrdr1 (apply instance)

                blrdr2

             

              Properties:

                DGConnectIdentifier            = 'blrdr'

                ObserverConnectIdentifier      = ''

                LogXptMode                      = 'ASYNC'

                RedoRoutes                      = ''

                DelayMins                      = '0'

                Binding                        = 'optional'

                MaxFailure                      = '0'

                MaxConnections                  = '1'

                ReopenSecs                      = '300'

                NetTimeout                      = '30'

                RedoCompression                = 'DISABLE'

                LogShipping                    = 'ON'

                PreferredApplyInstance          = ''

                ApplyInstanceTimeout            = '0'

                ApplyLagThreshold              = '0'

                TransportLagThreshold          = '0'

                TransportDisconnectedThreshold  = '30'

                ApplyParallel                  = 'AUTO'

                StandbyFileManagement          = 'AUTO'

                ArchiveLagTarget                = '0'

                LogArchiveMaxProcesses          = '5'

                LogArchiveMinSucceedDest        = '1'

                DbFileNameConvert              = '+ORADATA, +DATA'

                LogFileNameConvert              = '+ORADATA, +DATA'

                FastStartFailoverTarget        = 'blrdb'

                InconsistentProperties          = '(monitor)'

                InconsistentLogXptProps        = '(monitor)'

                SendQEntries                    = '(monitor)'

                LogXptStatus                    = '(monitor)'

                RecvQEntries                    = '(monitor)'

                StaticConnectIdentifier(*)

                StandbyArchiveLocation(*)

                AlternateLocation(*)

                LogArchiveTrace(*)

                LogArchiveFormat(*)

                TopWaitEvents(*)

                (*) - Please check specific instance for the property value

             

            Database Status:

            SUCCESS

             

            DGMGRL> exit

            • 3. Re: DGMGRL - FSFO Configuration with Maximum Performance Mode
              Dejan T.

              Ok, as I expected.

              Please, change the property LogXptMode to SYNC:

               

              dgmgrl> edit database blrdb set property LogXptMode='SYNC';

              dgmgrl> edit database blrdr set property LogXptMode='SYNC';

               

              and try again.

              • 4. Re: DGMGRL - FSFO Configuration with Maximum Performance Mode
                CloudDB

                DGMGRL> EDIT DATABASE 'blrdb' SET PROPERTY 'LogXptMode'='SYNC';

                Property "LogXptMode" updated

                DGMGRL>

                DGMGRL> EDIT DATABASE 'blrdr' SET PROPERTY 'LogXptMode'='SYNC';

                Property "LogXptMode" updated

                DGMGRL>

                DGMGRL> enable fast_start failover;

                Error: ORA-16693: requirements not met for enabling fast-start failover

                Failed.

                • 5. Re: DGMGRL - FSFO Configuration with Maximum Performance Mode
                  Dejan T.

                  Sorry, I overlooked that the configuration is in the MaxPerformance protection mode. Then ASYNC is also okay.

                   

                  Well, you need to enable flashback to fullfill tha FSFO requirement.

                  1 person found this helpful
                  • 6. Re: DGMGRL - FSFO Configuration with Maximum Performance Mode
                    CloudDB

                    Thanks for your valuable time.

                     

                    As I mention in thread,Solution we are looking for:

                    We want to configure Data guard - Data broker FSFO with Maximum Performance Mode.

                    We don't want to configure Flashback database on primary or standby.

                    We don't want to reinstate automatically.

                    • 7. Re: DGMGRL - FSFO Configuration with Maximum Performance Mode
                      CKPT

                      Hello Hitesh,

                       

                      When you tried to enable the FSFO it resulted the requirements are not met, You have also mentioned that you don't want to enable flashback.

                      Unfortunately FSFO uses flashback technology to reinstate the failed primary database in case of failover done by observer+broker.

                      So flashback is mandatory any how.

                       

                      Thanks.

                      • 8. Re: DGMGRL - FSFO Configuration with Maximum Performance Mode
                        CloudDB

                        Hi Basha,

                         

                        Thanks and Noted your point,

                        How to changed Auto-reinstate Configuration in dgmgrl ?

                         

                        show fast_start failover output having Auto-reinstate:    TRUE

                        Can we make it disable or off ==> Auto-reinstate:    FALSE

                         

                        Regards

                        Hitgon

                        • 9. Re: DGMGRL - FSFO Configuration with Maximum Performance Mode
                          CKPT

                          That can be done after you enable the FSFO, this can be achieved after you fulfill the requirements for observer.

                           

                          When you don't want to do reinstate feature then why you preferring to use Observer/FSFO?

                          • 10. Re: DGMGRL - FSFO Configuration with Maximum Performance Mode
                            CloudDB

                            Hi Basha,

                             

                            Thanks again,

                             

                            Currently Observer is already start from third machine

                            -bash-4.1$ dgmgrl sys/*********@blrdb

                            DGMGRL for Linux: Version 12.1.0.2.0 - 64bit Production

                            Copyright (c) 2000, 2013, Oracle. All rights reserved.

                             

                            Welcome to DGMGRL, type "help" for information.

                            Connected as SYSDBA.

                            DGMGRL> Start Observer

                            Observer started

                            Configuration from Primary Site

                            DGMGRL> show configuration

                            Configuration - DGConfig

                             

                              Protection Mode: MaxPerformance

                              Members:

                              blrdb - Primary database

                                blrdr - Physical standby database

                             

                            Fast-Start Failover: DISABLED

                             

                            Configuration Status:

                            SUCCESS   (status updated 38 seconds ago)

                            When you don't want to do reinstate feature then why you preferring to use Observer/FSFO?

                             

                            Requirement is that We only want the automatic failover and do not want to configure auto reinstate because auto reinstate will depend on Flashback functionality.

                            We have Performance SLA with our client application which needs response time in milliseconds so we don't want to take extra load of flashback functionality in our database.

                             

                            So we decided to use Maximum Performance mode while deploying the FSFO.

                            We agreed with this whitepaper  http://www.oracle.com/technetwork/articles/smiley-fsfo-084973.html

                            Oracle Database 11g FSFO adds support for Maximum Performance mode (async redo transfer), providing the flexibility to trade durability for performance.  Commit latency is not affected by redo transfer, but committed transactions whose redo has not been received by the standby will be lost during failover.  FSFO configurations in Maximum Performance mode may limit potential data loss by specifying the maximum allowable age of transactions that are lost during a failover. For example, if the limit specified is 30 seconds (the default), FSFO guarantees that all transactions that committed prior to 30 seconds ago are preserved during failover.  The minimum allowable limit is 10 seconds.

                            We want the partial functionality of FSFO, I mean to say that we want to automate the failover using observer FSFO Configuration but same time Instead of relay on Auto reinstate feature, we want to rebuild the new standby manually once old primary is comes up.

                             

                            Regards

                            Hitgon

                            • 11. Re: DGMGRL - FSFO Configuration with Maximum Performance Mode
                              Sven W.

                              CloudDB wrote:

                              ...

                              We have Performance SLA with our client application which needs response time in milliseconds so we don't want to take extra load of flashback functionality in our database.

                              ...

                              That is interesting to hear. Do you have specific test cases that prove that enabling flashback will lead to slower response time?

                              Imho flashback is a very core oracle functionality based upon UNDO data. Enabling it just means that part of this functionality is exposed to us to be used.

                              But even if you do not enable it this core functionality is still there. So I wonder where a relevant performance hit would be coming from.

                              Of cause for every feature there might be an overhead, but I wonder how you setup your tests and how big a difference was shown, that you came to so drastic conclusions.

                              • 12. Re: DGMGRL - FSFO Configuration with Maximum Performance Mode
                                CKPT

                                Yeah i understoood i mean to enable FSFO we need flashback not only observer. 

                                This is really interesting requirement. Not sure if there is any solution for your requirement but i would like to interpret this scenario very soon.

                                 

                                You got chance to check with Oracle if there is any possibility on this? Personally i never did such scenario ever..

                                Thank You.

                                1 person found this helpful
                                • 13. Re: DGMGRL - FSFO Configuration with Maximum Performance Mode
                                  Marco Mischke

                                  Hi all,

                                   

                                  there is a performance impact. Depends on where your flashback logs are and how heavy the system is loaded. We experienced a notable performance degradation some time ago:

                                   

                                  https://dbamarco.wordpress.com/2015/12/08/oda-performance-impact-due-to-flashback-database/

                                  1 person found this helpful
                                  • 14. Re: DGMGRL - FSFO Configuration with Maximum Performance Mode
                                    user11952722

                                    hi,

                                    if there is a fianal result or any successful  scenario  about your case?

                                     

                                    I am really interested on this problem.

                                     

                                    thank you.

                                     

                                    Best Regards.

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