[Opendnssec-develop] RE: Supporting downgrades

[Sara (Sinodun)]

On 12 Jul 2012, at 12:18, Rickard Bellgrim wrote:

>> The recent discussion on package contents has raised an interesting question - do we plan to provide migration scripts for users to downgrade between *major* versions e.g. 1.4.0 to 1.3.10. It does not appear that historically this has been done for previous releases.
> 
> Yes, that would be useful. A script called something like
> "migration-1.4.0.sh" where all migration code is gathered in one file
> for that version. If you do not run it with any arguments then you get
> some description on what versions you can upgrade from. If you run it
> with "-a" then you apply the changes. If you run with "-r" then you
> revert the changes.

I will open a ticket to address this in 1.4.

I also want to clarify something with regard to upgrades. 

1) AFAIK the db upgrade scripts provided for ODS would normally follow this kind of pattern:

1.3.x -> 1.4.0a1  (for testing)
1.3.x -> 1.4.0a2  (for testing)
1.3.x -> 1.4.0  (supported upgrade path)

So - in other words there wouldn't normally be a script provided for e.g. 1.4.0a1 -> 1.4.0 if it were needed. This is a major reason we recommend alphas are not used in production. 


2) In practice (and I think this holds for 1.4 so far) this hasn't been a problem because a migration script from an alpha to full release has never been needed. (Sion is best placed to answer this but he is on leave right now.)


The reason I ask is that Paul is using 1.4.0a1 in production and it may be the case that it remains in EPEL to be replaced by 1.4.0 when it is available.  So, if a script were to be needed, we might need to support users in the specific case of 1.4.0a1 -> 1.4.0. However I want to set expectations correctly in that this is not something we support in general. 

If anyone disagrees with this approach please let me know.