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https://issues.apache.org/jira/browse/KYLIN-5308?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17639925#comment-17639925
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ASF GitHub Bot commented on KYLIN-5308:
---------------------------------------

JialeHe opened a new pull request, #2039:
URL: https://github.com/apache/kylin/pull/2039

   Co-authored-by: Jiale He <[email protected]>
   
   ## Proposed changes
   
   Describe the big picture of your changes here to communicate to the 
maintainers why we should accept this pull request. If it fixes a bug or 
resolves a feature request, be sure to link to that issue.
   
   ## Branch to commit
   - [ ] Branch **kylin3** for v2.x to v3.x
   - [ ] Branch **kylin4** for v4.x
   - [x] Branch **kylin5** for v5.x
   
   ## Types of changes
   
   What types of changes does your code introduce to Kylin?
   _Put an `x` in the boxes that apply_
   
   - [x] Bugfix (non-breaking change which fixes an issue)
   - [ ] New feature (non-breaking change which adds functionality)
   - [ ] Breaking change (fix or feature that would cause existing 
functionality to not work as expected)
   - [ ] Documentation Update (if none of the other choices apply)
   
   ## Checklist
   
   _Put an `x` in the boxes that apply. You can also fill these out after 
creating the PR. If you're unsure about any of them, don't hesitate to ask. 
We're here to help! This is simply a reminder of what we are going to look for 
before merging your code._
   
   - [x] I have created an issue on [Kylin's 
jira](https://issues.apache.org/jira/browse/KYLIN), and have described the 
bug/feature there in detail
   - [x] Commit messages in my PR start with the related jira ID, like 
"KYLIN-0000 Make Kylin project open-source"
   - [x] Compiling and unit tests pass locally with my changes
   - [x] I have added tests that prove my fix is effective or that my feature 
works
   - [x] I have added necessary documentation (if appropriate)
   - [x] Any dependent changes have been merged
   
   ## Further comments
   
   If this is a relatively large or complex change, kick off the discussion at 
[email protected] or [email protected] by explaining why you chose the 
solution you did and what alternatives you considered, etc...
   




> The old transaction is not interrupted when Epoch renew retry
> -------------------------------------------------------------
>
>                 Key: KYLIN-5308
>                 URL: https://issues.apache.org/jira/browse/KYLIN-5308
>             Project: Kylin
>          Issue Type: Bug
>            Reporter: Jiale He
>            Assignee: Jiale He
>            Priority: Critical
>         Attachments: image-2022-11-28-16-32-00-356.png
>
>
> kylin fails to write data to the new transaction because the old transaction 
> is not interrupted during the Renew Epoch Retry. As a result, Kylin loses the 
> epoch.
>  
> When Epoch Renew occurs, the write to the database times out and tries again. 
> As the old transaction is not rolled back during the retry, the old 
> transaction is successfully written to the database and MVCC+1 occurs. When a 
> new transaction writes to the database, it will check the MVCC. If the 
> detection fails, kylin will think that the Epoch is lost.
> !image-2022-11-28-16-32-00-356.png!



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