[ 
https://issues.apache.org/jira/browse/HUDI-2119?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17373047#comment-17373047
 ] 

ASF GitHub Bot commented on HUDI-2119:
--------------------------------------

prashantwason opened a new pull request #3210:
URL: https://github.com/apache/hudi/pull/3210


   If the rolled-back instant was synced to the Metadata Table, a corresponding 
deltacommit with the same timestamp should have been created on the Metadata 
Table timeline. To ensure we can always perform this check, the Metadata Table 
instants should not be archived until their corresponding instants are present 
in the dataset timeline.
   
   ## *Tips*
   - *Thank you very much for contributing to Apache Hudi.*
   - *Please review https://hudi.apache.org/contributing.html before opening a 
pull request.*
   
   ## What is the purpose of the pull request
   
   
   ## Brief change log
   1. Check that the instant-being-rolled-back was commited to metadata table
   2. Keep larger number of instants in the metadata table timeline so the 
above check can be performed.
   
   ## Verify this pull request
   
   This pull request is already covered by existing tests for Metadata Table
   
   This change added tests to TestHoodieBackedMetadata
   
   ## Committer checklist
   
    - [ ] Has a corresponding JIRA in PR title & commit
    
    - [ ] Commit message is descriptive of the change
    
    - [ ] CI is green
   
    - [ ] Necessary doc changes done or have another open PR
          
    - [ ] For large changes, please consider breaking it into sub-tasks under 
an umbrella JIRA.


-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: commits-unsubscr...@hudi.apache.org

For queries about this service, please contact Infrastructure at:
us...@infra.apache.org


> Syncing of rollbacks to metadata table does not work in all cases
> -----------------------------------------------------------------
>
>                 Key: HUDI-2119
>                 URL: https://issues.apache.org/jira/browse/HUDI-2119
>             Project: Apache Hudi
>          Issue Type: Bug
>            Reporter: Prashant Wason
>            Assignee: Prashant Wason
>            Priority: Blocker
>             Fix For: 0.9.0
>
>
> This is an issue with inline automatic rollbacks.
> Metadata table assumes that a rollbacks is to be applied if the 
> instant-being-rolled back has a timestamp less than the last deltacommit time 
> on the metadata timeline. We do not explicitly check if the 
> instant-being-rolled-back was actually written to metadata table.
> **A rollback adds a record to metadata table which "deletes" files from a 
> failed/earlier commit. If the files being deleted were never actually 
> committed to metadata table earlier, the deletes cannot be consolidated 
> during metadata table reads. This leads to a HoodieMetadataException as we 
> cannot differentiate this from a bug where we might have missed committing a 
> commit to metadata table.
>  
>  



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

Reply via email to