Querying about rollback/downgrade of JIRA application

[Nalini Kumar]

Hello Community,

We are having a Data center installation of JIRA and currently using 8.5.4. We are planning to upgrade it to 8.13.X version. I already upgraded in my DEV environment successfully and tested it.
My question is related to rolling back it to 8.5.4 if anything wrong happens after the upgrade during post testing. I tried rolling back, by copying the files of 8.5.4 back and during startup I am seeing these logs.

[c.a.jira.startup.DefaultJiraLauncher] JIRA has failed to start because of the following errors: [(Event: Level = (EventLevel: fatal) , Key = (EventType: database) , Desc = Failed to start JIRA due to a build number inconsistency. , Exception = The version of the data present in your database is higher than the version of JIRA you are trying to start.<br/><ul><li>Database build number: <strong>813009</strong></li><li>JIRA app build number: <strong>805004</strong></li></ul><br/>The best solution is to upgrade JIRA to a version that is equal or higher than the version of your data.<br/>You could also try to downgrade your current database build version to match the version of JIRA you are trying to start.<br/>Review our documentation and try what works for you.<br/>)]

I tried adding this parameter to setenv.sh and startup was successful. But this parameter is not present in any of the Documentation provided by Atlassian. So is it recommended or is there any other tested way for rolling back.

JVM_SUPPORT_RECOMMENDED_ARGS="-Djira.downgrade.allowed=true"

[Nic Brough -Adaptavist- · Accepted solution]

That downgrade flag is terribly misleading - it really doesn't allow for any useful form of downgrade.  It's certaintly pretty much useless outside point releases (e.g. 8.5.4 to 8.5.3 might be ok, but there's no chance of 8.5.anything going down to 8.4.anything)

As a general rule, you can not safely or reliably downgrade an Atlassian application.  The way to roll back an upgrade is to restore the database backup you took before applying the upgrade, then point the old installation at it. 

[Nalini Kumar]

Thanks for the reply.
So just want to confirm again that the parameter "-Djira.downgrade.allowed=true" is not useful with downgrade/rollback from 8.13.X to 8.5.X??
Only way to do is through restoring from DB??

[Nic Brough -Adaptavist-]

The way to roll back an upgrade is to restore the database backup you took before applying the upgrade, then point the old installation at it. 

[Shahrul Saifuddin]

what do you mean by pointing it to an old installation? may I get the steps on how to do it?

[Nic Brough -Adaptavist-]

You work out or remember exactly what version the database backup is on. 

Download and install that version, and get it running, pointed at an empty database and with the single new admin account, and get it through to the point where a demo or empty space has been created

Stop it, change the confluence.cfg.xml (might have a slightly different name, but it's in the Confluence home directory), so that it points to the old restored database and restart it.  Run a full re-index.