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Connor McDonald

Thanks for the question, Geraldo.

Asked: May 20, 2020 - 4:03 am UTC

Answered by: Connor McDonald - Last updated: May 26, 2020 - 1:26 am UTC

Category: Database Administration - Version: 18.6

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You Asked

Hello, Ask TOM Team.

I have a 2-node RAC production database (18.6) with Data Guard configured (using data guard broker). My app's connection strings are pointing to scan-name\db-service.

What are the steps to make a database switchover without making any changes in application connection strings?

Thanks in advanced.

Regards,

and we said...

Your connection strings must know of both primary and standby clusters, and have the ability to switchover between the two, for example:

sales =
   (DESCRIPTION= 
     (FAILOVER=ON)
     (CONNECT_TIMEOUT=5)
     (ADDRESS_LIST=
       (ADDRESS=(HOST=boston-scan)(PORT=1521))
       (ADDRESS=(HOST=dallas-scan)(PORT=1521)))
     (CONNECT_DATA=(SERVICE_NAME=sales)))


You then define your services so that they operate on node(s) only when they are the primary

srvctl add service –db NORTH –service PAYROLL –role PRIMARY ....



There is a comple walk through of the switchover steps in the DataGuard documentation

https://docs.oracle.com/en/database/oracle/oracle-database/19/dgbkr/using-data-guard-broker-to-manage-switchovers-failovers.html#GUID-05918DD1-FB0F-435B-873B-A43BEC1C7638

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Reviews

Review

May 22, 2020 - 1:09 am UTC

Reviewer: A reader

Thanks for the help.

I will check the documentation.

Regards,

Another point to take note

May 22, 2020 - 6:54 am UTC

Reviewer: A reader

What I have had experienced was that in spite of the settings applications using JDBC would go to the standby DB and error out as a result.

So, it is recommended that you have RETRY_COUNT set in the TNS entry so that it will attempt to connect to the PRIMARY in case of an error.

Cheers



Connor McDonald

Followup  

May 26, 2020 - 1:26 am UTC

Thanks for the info

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