[openstack-dev] [upgrades][skip-level][leapfrog] - RFC - Skipping releases when upgrading

Dan Smith dms at danplanet.com
Fri May 26 16:38:39 UTC 2017


> I haven't looked at what Keystone is doing, but to the degree they are
> using triggers, those triggers would only impact new data operations as
> they continue to run into the schema that is straddling between two
> versions (e.g. old column/table still exists, data should be synced to
> new column/table).   If they are actually running a stored procedure to
> migrate existing data (which would be surprising to me...) then I'd
> assume that invokes just like any other "ALTER TABLE" instruction in
> their migrations.  If those operations themselves rely on the triggers,
> that's fine.

I haven't looked closely either, but I thought the point _was_ to
transform data. If they are, and you run through a bunch of migrations
where you end at a spot that expects that data was migrated while
running at step 3, triggers dropped at step 7, and then schema compacted
at step 11, then just blowing through them could be a problem. It'd work
for a greenfield install no problem because there was nothing to
migrate, but real people would trip over it.

> But a keystone person to chime in would be much better than me just
> making stuff up.

Yeah, same :)

--Dan



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