freemandealer opened a new pull request, #48687:
URL: https://github.com/apache/doris/pull/48687

   The initialization of the file cache involves asynchronous loading logic and 
synchronous upgrade directories. The latter mainly handles the conversion from 
version1 to version2 format and some fallback logic for problematic 
directories, which involves a large number of directory traversals and can be 
very slow.
   
   Previously, in PR #44429, we changed the initialization of multiple cache 
directories from parallel to serial to avoid the disorder caused by concurrent 
initialization, which led to a long cache initialization time and affected the 
startup speed of the BE.
   
   We found that the upgrade directory is only meaningful during upgrades and 
does not need to be executed on every restart. Therefore, if we detect that the 
version file has been successfully written, we consider the cache directory to 
have completed the upgrade and skip these redundant directory traversals
   
   Of course, we could further optimize the directory traversal process to make 
it asynchronous and not block the BE startup. However, this would result in 
three concurrent operations on the file system: asynchronous loading, 
asynchronous updating, and lazy loading on query. This would increase code 
complexity, the likelihood of errors, and the difficulty of troubleshooting. 
Considering that old clusters are not very common and that a cluster only needs 
to go through such an upgrade once in its lifecycle, we assessed that this 
optimization would have low cost-effectiveness and decided not to pursue it.
   
   ### What problem does this PR solve?
   
   Issue Number: close #xxx
   
   Related PR: #xxx
   
   Problem Summary:
   
   ### Release note
   
   None
   
   ### Check List (For Author)
   
   - Test <!-- At least one of them must be included. -->
       - [ ] Regression test
       - [ ] Unit Test
       - [ ] Manual test (add detailed scripts or steps below)
       - [ ] No need to test or manual test. Explain why:
           - [ ] This is a refactor/code format and no logic has been changed.
           - [x] Previous test can cover this change.
           - [ ] No code files have been changed.
           - [ ] Other reason <!-- Add your reason?  -->
   
   - Behavior changed:
       - [x] No.
       - [ ] Yes. <!-- Explain the behavior change -->
   
   - Does this need documentation?
       - [x] No.
       - [ ] Yes. <!-- Add document PR link here. eg: 
https://github.com/apache/doris-website/pull/1214 -->
   
   ### Check List (For Reviewer who merge this PR)
   
   - [ ] Confirm the release note
   - [ ] Confirm test cases
   - [ ] Confirm document
   - [ ] Add branch pick label <!-- Add branch pick label that this PR should 
merge into -->
   
   


-- 
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...@doris.apache.org

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


---------------------------------------------------------------------
To unsubscribe, e-mail: commits-unsubscr...@doris.apache.org
For additional commands, e-mail: commits-h...@doris.apache.org

Reply via email to