06-29-2016 03:18 PM - edited 06-29-2016 03:19 PM
If I want to back out from the hotfix I alredy applied what should I do ?
Do I just restore the backup taken ? or is there any another procedure ?
If restoring the backup (i mean backup of both config and home directories...for example "SAS94BASEprod" which consists SAS_94 and config directories) is an option ..what are the things needed to do.. just rename the backup to original name ? (for example.. rename "SAS94BASEprod_proir_hotfix" to "SAS94BASEprod") thats all?
06-29-2016 04:55 PM
Hotfixes can range from a simple version bump of a single file to a whole set of files plus updates to metadata, configuration and rebuild/redeployment ofd midtier components. I doubt there would be a viable one-size-fits-all apporach to reverting any hotfix other than going back in time by restoring a backup. And then that backup would involve a concise set of all of the above: binaries, metadata, configuration, content in the content server, framework database. Possibly destroying user data in the process. Also there is the deployment registry that needs to be updated to the new situation. In all, an intricate network of relationships that is easily disturbed. We now have the Backup&Restore Tool that takes care of this.
Simple hotfixes leave a log of files replaced and you may find it easy to undo. Also we have seen new hotfixes that aim at reverting existing ones due to adverse effects.
In this respect we may conclude that the SAS9 deployment has become convoluted over the years. No surprise SAS Vaiya is at the horizon, promising to take care of a lot of these and reated deployment headaches that are now synonymous to SAS (and probably bringing a few new ones).
Oke, enough. Off the soap box.
06-30-2016 03:40 AM
Hi, as @jklaverstijn mentioned, some of them you can backtrack thanks to the logs and instructions, some of them are harder to rollback or preferable not to rollback.
Something that can help is version control (SVN, CVS, Git, etc). Tee same that you can create branches on code and rollback to previous states, you can have versioning on any file system element, such as SAS binaries and SAS configuration.
This will be always much better than recovering from a backup and such other nasty procedures.
I cannot ensure anything of course, but I have the feeling that SAS Viya will have more integration with version control.
In the meantime, you can have a look to a SAS paper/proceeding provided by Alec Fernandez, Preparing for a SAS® 9.4 Deployment and Managing That Deployment Throughout Its Lifecycle: http://support.sas.com/resources/papers/proceedings16/SAS6501-2016.pdf
For now, you can do it, and be mindful when taking the decission of rolling back a hotfix.
07-01-2016 02:10 AM
if your servers on VM's take snapshots before applying the hotfix and roll back if the changes are not good.
07-01-2016 10:13 AM
A VM snapshot recovery will work only if there is no user content (metadata, filesystem, dbs, etc) modified in the time between you applied the hotfix and you actually recover from it. Otherwise users will lose their data.
Therefore your approach is OK if the recovery is inmediate after you apply the hotfix and it doesn't work. But if you apply the hotfix, everything seems just fine and after a couple of days (or 1 month) the users say " this isn't working as expected" or you find other kind of problems and you need to recover to a previous state... then you need a different approach.