[
https://issues.apache.org/jira/browse/HADOOP-14335?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15978608#comment-15978608
]
Steve Loughran commented on HADOOP-14335:
-----------------------------------------
I added the version in there so we can at least recognise that there are
version mismatches; without that we'd be stuck. At least now we can recognise
the problem.
I didn't add any logic about forward/backward compat as I didn't know what to
add. Same for an update tool: didn't write one until is was needed
Maybe we could add a minor version marker and have logic of "guaranteed
compatibility across minor versions, but not major ones".
One aspect of table update is we may also want to add an offline marker to the
DB too; when doing a schema update or other maintenance, you should be able to
mark the DB as offline; clients would be expected to see this and for non-auth:
downgrade, for auth: fail.
> Improve DynamoDB schema update story
> ------------------------------------
>
> Key: HADOOP-14335
> URL: https://issues.apache.org/jira/browse/HADOOP-14335
> Project: Hadoop Common
> Issue Type: Sub-task
> Components: fs/s3
> Affects Versions: HADOOP-13345
> Reporter: Sean Mackrory
> Assignee: Sean Mackrory
>
> On HADOOP-13760 I'm realizing that changes to the DynamoDB schema aren't
> great to deal with. Currently a build of Hadoop is hard-coded to a specific
> schema version. So if you upgrade from one to the next you have to upgrade
> everything (and then update the version in the table - which we don't have a
> tool or document for) before you can keep using S3Guard. We could possibly
> also make the definition of compatibility a bit more flexible, but it's going
> to be very tough to do that without knowing what kind of future schema
> changes we might want ahead of time.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
