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SQL Server cluster and rolling DDL upgrades RRS feed

  • Question

  • Is it possible to perform rolling or online DDL upgrades to SQL DB either clustered or mirrored? Can anyone provide a list of steps or guide me to some documentation?

    Friday, September 24, 2010 3:22 PM

Answers

  • Unless you have the option to modify your app so it logs all modifications done during the upgrade and you can use that log ro roll them ontis the "old system" in case the upgrade fails, I think your only option is to designate the system as read-only during the upgrade. That way you can roll-back your upgrade by just restoring a backup of the database (or reverting to a database snapshot in case you have Enterprise Edition). I can't see how anything else would be workable, but perhaps others out there has some clever ideas?


    Tibor Karaszi, SQL Server MVP | web | blog
    Wednesday, September 29, 2010 4:34 PM
    Moderator

All replies

  • You mean in the sense that if the upgrade fails, you want to ignore it and designate the "failover machine" as the "primary" and keep working on the old data? Or something else?
    Tibor Karaszi, SQL Server MVP | web | blog
    Friday, September 24, 2010 3:35 PM
    Moderator
  • Thanks for responding Tibor

    Yes

    Friday, September 24, 2010 9:08 PM
  • Cluster won't help you since there is only one set of data (the common disk). What is you goal?

    a) Being able to rollback the upgrade in case it didn't work out well?

    b) Being able to work against the database while the upgrade is being prformed, unaffected by the upgrade? If so, how do you plan to handle modifications done against the database done while upgrade was in progress, in case you decide to rollback the upgrade?


    Tibor Karaszi, SQL Server MVP | web | blog
    Saturday, September 25, 2010 8:00 AM
    Moderator
  • Tibor,

    Thanks for your response. You have good questions and I have the same as well. I am looking for answers to the same questions. How does the SQL community handle database upgrades without downtime? How would you handle this?

     

    Any guidance is much appreciated.

    Wednesday, September 29, 2010 2:19 PM
  • Unless you have the option to modify your app so it logs all modifications done during the upgrade and you can use that log ro roll them ontis the "old system" in case the upgrade fails, I think your only option is to designate the system as read-only during the upgrade. That way you can roll-back your upgrade by just restoring a backup of the database (or reverting to a database snapshot in case you have Enterprise Edition). I can't see how anything else would be workable, but perhaps others out there has some clever ideas?


    Tibor Karaszi, SQL Server MVP | web | blog
    Wednesday, September 29, 2010 4:34 PM
    Moderator