Quanlong Huang has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/21665 )

Change subject: IMPALA-12865: Fix wrong lastRefreshEventId set by firing RELOAD 
events
......................................................................


Patch Set 16:

(1 comment)

http://gerrit.cloudera.org:8080/#/c/21665/16/fe/src/main/java/org/apache/impala/service/CatalogOpExecutor.java
File fe/src/main/java/org/apache/impala/service/CatalogOpExecutor.java:

http://gerrit.cloudera.org:8080/#/c/21665/16/fe/src/main/java/org/apache/impala/service/CatalogOpExecutor.java@7174
PS16, Line 7174:         currentHMSEventId = eventIds.get(0);
> I want to update currentHMSEventId, if the latestEventId and currentEventId
Is this required to fix the test failure? It seems we can further optimize it 
that if there are no events on this table between currentHMSEventId and 
eventIds.get(0), we can set lastRefreshEventId to eventIds.get(0) to skip 
processing this RELOAD event. However, it's hard to check this for 
transactional tables since CommitTxnEvent and AbortTxnEvent don't have the 
table names. Maybe we can just do it for non-transactional tables. We can 
discuss this in a future JIRA.

More importantly, we need to improve the logic of skipping self RELOAD events. 
Currently we just check the lastRefreshEventId: 
https://github.com/apache/impala/blob/d086babdbd249df0069900739f24da280b06a279/fe/src/main/java/org/apache/impala/catalog/events/MetastoreEvents.java#L3134-L3137
This is sufficient to skip self-events before we fix the wrong 
lastRefreshEventId. Now after this fix, we can only skip the ReloadEvent when 
it's exactly the next event after currentHMSEventId. This might be rare in a 
real cluster that have lots of activities. Then each REFRESH will reload the 
table twice. The second reload happens in processing the self RELOAD event. I 
think we should avoid this regression in this patch. Maybe reusing the 
InFlightEvents used in other event types. I would like to hear your thoughts.



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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: I90039da77ec561c5aede44456f88c6650582815b
Gerrit-Change-Number: 21665
Gerrit-PatchSet: 16
Gerrit-Owner: Sai Hemanth Gantasala <[email protected]>
Gerrit-Reviewer: Csaba Ringhofer <[email protected]>
Gerrit-Reviewer: Impala Public Jenkins <[email protected]>
Gerrit-Reviewer: Quanlong Huang <[email protected]>
Gerrit-Reviewer: Sai Hemanth Gantasala <[email protected]>
Gerrit-Comment-Date: Thu, 12 Dec 2024 13:03:55 +0000
Gerrit-HasComments: Yes

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