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https://jira.duraspace.org/browse/DS-712?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Tim Donohue updated DS-712:
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Priority: Critical (was: Blocker)
Attachment: update-sequences-postgres.patch
I've decided to take a slightly different route to resolving this issue for AIP
restores.
I've attached a patch that makes a change to the 'update-sequences.sql' script
for PostgreSQL (still working on an Oracle version -- will be attached as soon
as I complete it). This patch changes how the 'handle_seq' is updated, such
that it is now based on the *maximum handle suffix* rather than the maximum
value of 'handle_id' in the 'handle' table.
So, as an example, if your maximum handle was "123456789/6647", but the maximum
'handle_id' is just 102, then running 'update-sequences.sql' would update your
'handle_seq' to 6647 (which means the next handle created will be
123456789/6648). Previously, it would have updated the value to 102 (which,
as described above, could result in conflicts in your DB).
In the end, if the 'update-sequences.sql' script is properly updating the
'handle_seq' to avoid conflicts, then we can just recommend to *always* run
'update-sequences.sql' after a major AIP restore or replace. This will ensure
the DB never enters an unstable state.
Comments or counter-proposals welcome!
> DSpace Fails to Check if a Handle is already assigned before assigning a new
> handle
> -----------------------------------------------------------------------------------
>
> Key: DS-712
> URL: https://jira.duraspace.org/browse/DS-712
> Project: DSpace
> Issue Type: Bug
> Components: DSpace API
> Affects Versions: 1.7.0
> Reporter: Tim Donohue
> Assignee: Tim Donohue
> Priority: Critical
> Fix For: 1.7.0
>
> Attachments: update-sequences-postgres.patch
>
>
> Not sure how this hasn't come up before, but I just noticed this in terms of
> testing the new AIP Backup/Restore functionality (DS-466).
> DSpace currently makes a highly flawed assumption when assigning new Handles.
> It will *always* assign a Handle equal to the next available value in the
> 'handle_seq' (which is just the max value of 'handle_id' in the 'handle'
> table). See the HandleManager.createHandle() method.
> This becomes extremely fragile when you have content which has been migrated
> or restored from another DSpace (for example, via the AIP backup/restore
> feature). In those instances, it you may end up restoring/migrating content
> that looks like this:
> handle_id = 44 (or whatever the next value in 'handle_seq' is)
> handle = 123456789/50 (or whatever the restored handle should be)
> Once the value of 'handle_id' reaches the suffix value of a restored handle,
> then you will run into database conflicts & will be unable to submit any new
> content into DSpace. So, in the above example, as soon as 'handle_seq" gets
> to the value of 50, Dspace will attempt to assign a new handle of
> '123456789/50' to the next object created. However, as that handle is
> already in use, the new object will always fail to be created. In other
> words, the DSpace system will fail to accept any new objects.
> The fix would be to first ensure a handle is *not* already in use before
> assigning it -- essentially looking for the next available handle (rather
> than the next value of 'handle_seq") before assigning the handle. However, I
> need to determine a reasonable way to locate the next available handle
> (preferably something that will scale relatively well for larger installs).
> Ideas / thoughts / brainstorms welcome. I've marked this as a "Blocker" for
> DSpace 1.7.0, as it essentially makes your DSpace unusable if you were to
> encounter this bug. (The only way to get around this issue if you
> encountered it is to manually increase your "handle_seq" so that it's greater
> than the largest handle suffix in your system.)
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