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.

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                • 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.

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                              • 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 位用户发现它有用
                                • 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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