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    DG Broker Setup

    Jimbo

      Hi,

       

      I am currently setting up a Data Guard environment to make use of the Broker and I have a some basic queries –

       

      I have created a DG configuration on my Primary Instance ( I have not yet enabled the configuration ).

       

      Q1. Do I need to manually replicate the DG configuration on the Standby Databases by repeating the same dgmgrl entries ?

       

      Q2. The 11gR2 Broker Manual states that the databases and Data Guard Broker Config must be set to Max Protection. Yet I have seen other docs that state it can be set to Max Availability. Which mode needs to be used ?

       

      Q3. Is it possible for the Databases to be using one mode but the DG Broker Config to be set to another mode i.e. do you set the mode on the databases and the Broker separately or does the Broker simply pick up the mode that the databases are using ?

       

      Q4. At the moment my protection mode is Max Performance – so do I just need to simply need to change the protection mode used by the databases or is it possible to use DG Broker with Max Performance mode ?

       

      Q5. Do any of my databases need to have Flashback Database enabled if I am using DG Broker ?

       

      Q6. For a failover, do I simply go into dgmgrl of one of my Standby Instances and issue ‘failover to <standby_name>’;

       

      any help greatly appreciated

      Jim

        • 1. Re: DG Broker Setup
          mseberg

          Q1. Do I need to manually replicate the DG configuration on the Standby Databases by repeating the same dgmgrl entries ?

           

           

          No, but you need to Enable Broker both on primary database and standby database:

           

          alter system set dg_broker_start=TRUE scope=both;

           

          Make sure the primary and standby databases up and running when you do the setup

           

           

          Q2. The 11gR2 Broker Manual states that the databases and Data Guard Broker Config must be set to Max Protection. Yet I have seen other docs that state it can be set to Max Availability. Which mode needs to be used ?

           

          Your mode could be MaxPerformance

           

          Protection Mode: MaxPerformance

           

          Use "show configuration;" to display

           

          Q3. Is it possible for the Databases to be using one mode but the DG Broker Config to be set to another mode i.e. do you set the mode on the databases and the Broker separately or does the Broker simply pick up the mode that the databases are using ?

           

          If I understand the question correctly then yes.

           

           

          Q4. At the moment my protection mode is Max Performance so do I just need to simply need to change the protection mode used by the databases or is it possible to use DG Broker with Max Performance mode ?

           

          It's possible

           

          Q5. Do any of my databases need to have Flashback Database enabled if I am using DG Broker ?

           

          No. But it's a good idea. Flashback database and Fast Recovery Area will save you if you do a failover.

           

          Q6. For a failover, do I simply go into dgmgrl of one of my Standby Instances and issue ‘failover to <standby_name>’;

           

          Yes.

           

          DGMGRL> failover to...;

           

          I would stop and consider the recovery from a failover before doing one. For example is the outage less then the recovery time from the failover?

           

          Or will the failover cause more issues than it solves?

           

          Can I use a switchover instead?

           

           

          Best Regards

           

          mseberg

          • 2. Re: DG Broker Setup
            Mahir M. Quluzade

            Hi Jimbo

             

            First of all, if you are using DGMGRL - Broker - Managed Data  Guard configuration, then you must use DGMGRL for all changes on your databases.

             

            I have created a DG configuration on my Primary Instance ( I have not yet enabled the configuration ).

             

            You must add your standby database to this configuration, and enable DG configuration.

             

            Q1. Do I need to manually replicate the DG configuration on the Standby Databases by repeating the same dgmgrl entries ?

             

            Not need any manually replicate the DG configuration on the standby database. When you add standby database to  DG configuration.

            Then DGMGRL will create automatically same configuration on both side.(in dg config file)

             

            Q2. The 11gR2 Broker Manual states that the databases and Data Guard Broker Config must be set to Max Protection. Yet I have seen other docs that state it can be set to Max Availability. Which mode needs to be used ?

             

            You must use DGMGRL>  edit configuration set protection mode as MaxProtection;  command for setting Protection mode on DG configuration.

            Don't  forget LogXpt property must be SYNC on both  side.

             

            Q3. Is it possible for the Databases to be using one mode but the DG Broker Config to be set to another mode i.e. do you set the mode on the databases and the Broker separately or does the Broker simply pick up the mode that the databases are using ?

             

            It is not possible. When you set protection mode, it is changind on database protection mode.

            If it is different, then you get error on DG configuration.

             

            Q4. At the moment my protection mode is Max Performance – so do I just need to simply need to change the protection mode used by the databases or is it possible to use DG Broker with Max Performance mode ?

             

            Maximum Performace mode is defult protection mode.

             

            Q5. Do any of my databases need to have Flashback Database enabled if I am using DG Broker ?

             

            It is optional and you can  use DGMGRL without flashback enable. Flashback enable + Real time apply is best practice instead of DELAY option. 

             

            Q6. For a failover, do I simply go into dgmgrl of one of my Standby Instances and issue ‘failover to <standby_name>’;

             

            Yes. Additionaly you can use Fast Start  Failover with  DGMGRL.

             

            Regards

            Mahir M. Quluzade

            • 3. Re: DG Broker Setup
              Mahir M. Quluzade

              Dear my friend mseberg, our answers approximately same.

              But there have different answer on  Q3.

               

              He is asking : Is it possible for the Databases to be using one mode but the DG Broker Config to be set to another mode

              I answered:  It is not possible. When you set protection mode, it is changind on database protection mode.If it is different, then you get error on DG configuration.

               

              Can you check please?

               

              Regards

              Mahir M. Quluzade

              • 4. Re: DG Broker Setup
                mseberg

                If that's what he's asking then you are correct. I was thinking a different question and my supply of coffee is low.

                 

                Best Regards

                 

                mseberg

                • 5. Re: DG Broker Setup
                  Ivica Arsov

                  Hi


                  Just to add

                  As I know the DGMGRL will throw an error, but I think you can have difference in some of the parameters, for example in LOG_ARCHIVE_DEST_N parameters. In that case the DGMGRL will show a warning message that the parameters are not consistent in spfile and dg configuration files.

                   

                  I.Arsov

                  • 6. Re: DG Broker Setup
                    Mahir M. Quluzade

                    IvicaArsov wrote:

                     

                    Hi


                    As I know the DGMGRL will throw an error, but I think you can have difference in some of the parameters, for example in LOG_ARCHIVE_DEST_N parameters. In that case the DGMGRL will show a warning message that the parameters are not consistent in spfile and dg configuration files.

                     

                    I.Arsov

                    If parameters is different  between spfile and DG config file, then we are getting warning as you say.

                    We are some time getting this warning for example: DB_FILE_NAME_CONVERT and LOG_FILE_NAME_CONVERT parameters when inconsistent.

                    This parameters is static parameters, so need change this parameters in spfile.

                    and need restart for take effect, after restart we getting warning  on DG config becuase, we changed on SPFILE only.

                    Then we must change this parameters with DGMGRL>  edit database <> set property DbFileNameConvert=...

                     

                    Regards

                    Mahir M. Quluzade

                    • 7. Re: DG Broker Setup
                      Jimbo

                      Q1. Do I need to manually replicate the DG configuration on the Standby Databases by repeating the same dgmgrl entries ?

                      >> No, but you need to Enable Broker both on primary database and standby database:

                      alter system set dg_broker_start=TRUE scope=both;

                      Make sure the primary and standby databases up and running when you do the setup

                       

                      Yes that was one of the things that confused me. So if I create a DG Config whilst connected to the primary database, the same config will be duplicated from the DG Config files on the primary to the DG Broker Config files on all my standbys ( or at least those included in the DG Broker Config ) - is that correct ?

                       

                      I was a bit confused about whether or not the broker in essence was logically a single entity covering the primary and all the standby databases ( at least all those databases included in the DG Broker config ). I think the fact that each instance has its own DMON was making me think that each instance had its own Broker ( and hence I though I would need to duplicate the config on each broker ), whereas I think the reality is that there is really only 1 overarching broker and that the DMONS on each instance communicate with each other, in effect giving a single logical broker - is that closer to the mark ?

                       

                      thanks,

                      Jim

                      • 8. Re: DG Broker Setup
                        mseberg

                        Hello;

                         

                        You can check after creating the setup for the files on the Standby system.

                         

                        Example

                         

                        dbs/dr1@.dat

                        dbs/dr2@.dat

                         

                         

                        This note is worth a look
                        How to Safely Remove a Data Guard Broker Configuration (Doc ID 261336.1)
                        Best Regards
                        mseberg
                        • 9. Re: DG Broker Setup
                          Mahir M. Quluzade

                          Jimbo wrote:

                           

                          Yes that was one of the things that confused me.So if I create a DG Config whilst connected to the primary database,

                          the same config will be duplicated from the DG Config files on the primary to the DG Broker Config files on all my standbys ( or at least those included in the DG Broker Config ) - is that correct ?

                          Same config file is not duplicated to standby side. When you create DG configuration, then DGMGRL automatically  create config files.

                          If you add standby  to configuration, then DGMGRL creating config files to  standby side and writing same configuration to config files on standby  side.

                          It means, you  can not use standby config files on primary side. Because it is not duplicated files.

                           

                          I was a bit confused about whether or not the broker in essence was logically a single entity covering the primary and all the standby databases ( at least all those databases included in the DG Broker config ).

                          I think the fact that each instance has its own DMON was making me think that each instance had its own Broker ( and hence I though I would need to duplicate the config on each broker )

                          , whereas I think the reality is that there is really only 1 overarching broker and that the DMONS on each instance communicate with each other, in effect giving a single logical broker - is that closer to the mark ?

                          Not understandable question. Please write again. The Data Guard monitor process (DMON) is an Oracle background process that runs for every database instance that is managed by the broker.

                          When you start the Data Guard broker, a DMON process is created.

                           

                          Regards

                          Mahir M. Quluzade

                          • 10. Re: DG Broker Setup
                            Jimbo

                            I guess what I am trying to say is - is the Broker a single logical entity served by the DMON's on each instance or is each DMON in fact a broker on each instance ?

                             

                            I am guessing really the Broker should be viewed as a single logical entity since when you create a Broker Config on 1 instance ( say the primary ) it is replicated to each of the Standbys included in the Broker Config

                             

                            Jim


                            • 11. Re: DG Broker Setup
                              mseberg

                              I think of it more as a utility allowing centralized control of a Data Guard configuration. DMON is the background process for Broker. It is started if you set the initialization parameter DG_BROKER_START to TRUE.

                               

                              Here's a site I like:

                               

                              http://satya-dba.blogspot.com/2010/09/dgmgrl-utility-tool-executable.html

                               

                              Best Regards

                               

                              mseberg

                               

                              Message was edited by: mseberg

                              • 12. Re: DG Broker Setup
                                Jimbo


                                Yeah, that the wierd bit - you think of it as a centralized tool but effectively it is not installed centrally unless you choose to put DGMGRL on a separate management server ( but even then it is not really centralized installation as it is the local DMON's that are controlling things and the DGMGRL on the management server is simply a remote client end - it's a bit like having the RMAN client on a remote machine )

                                • 13. Re: DG Broker Setup
                                  Jimbo

                                  IvicaArsov wrote:

                                   

                                  Hi


                                  Just to add

                                  As I know the DGMGRL will throw an error, but I think you can have difference in some of the parameters, for example in LOG_ARCHIVE_DEST_N parameters. In that case the DGMGRL will show a warning message that the parameters are not consistent in spfile and dg configuration files.

                                   

                                  I.Arsov

                                   

                                  It's funny you should mention about DGMGRL giving inconsistent warnings / errors. I have a primary, a physical standby and a logical standby

                                  . I entered all 3 into my Broker Configuration. However when I tried to enable the Broker Configuration I got a number of inconsistencies on the Logical Standby

                                   

                                  DGMGRL> show database 'STANDBYL' InconsistentProperties;

                                  INCONSISTENT PROPERTIES

                                     INSTANCE_NAME              PROPERTY_NAME                MEMORY_VALUE         SPFILE_VALUE         BROKER_VALUE

                                          STANDBYL                                    ArchiveLagTarget                                    0                                                                       0

                                          STANDBYL                    LogArchiveMinSucceedDest    1                                                                       1

                                          STANDBYL                                     LogArchiveTrace                    0                                    (missing)                      0

                                          STANDBYL                                    LogArchiveFormat                    %t_%s_%r.dbf                  (missing)                      %t_%s_%r.dbf

                                   

                                  The Wierd thing is that when I check the DB parameters on primary, physical standby and logical standby - there is no difference, so why am I having to change the parameters for the logical standby ( STANDBYL ), why did it not also complain about my Physical Standby ?

                                   

                                  Any ideas ?

                                  Jim

                                  • 14. Re: DG Broker Setup
                                    Ivica Arsov

                                    Hi,

                                     

                                    Try to configure the parameters values from DGMGRL with EDIT DATABASE ... SET PROPERTY and then again check for inconsistent properties.

                                    This often happens when you configure the Data Guard Broker and change the parameters with alter system (not with DGMGRL). Always use DGMGRL to update the parameters which also updates the SPFILE.

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