Vihang Karajgaonkar has posted comments on this change. ( http://gerrit.cloudera.org:8080/17253 )
Change subject: IMPALA-6671: Change wait for sync ddl timeout ...................................................................... Patch Set 4: (1 comment) http://gerrit.cloudera.org:8080/#/c/17253/4/fe/src/main/java/org/apache/impala/catalog/CatalogServiceCatalog.java File fe/src/main/java/org/apache/impala/catalog/CatalogServiceCatalog.java: http://gerrit.cloudera.org:8080/#/c/17253/4/fe/src/main/java/org/apache/impala/catalog/CatalogServiceCatalog.java@3094 PS4, Line 3094: long maxNumAttempts = 5; > Ah, I see. After thinking this more clear, I think my idea should be changi "Now when skipping locked table is enabled, more rounds of topic updates could be sent in the time range between t1-a and t1-b. So 'maxNumAttempts' is reached quickly if it's still 5" Yes, that is exactly the problem that this patch is trying to address. However, in my opinion the number of topic updates which will skip the locked table is non-deterministic and depends on how long the table is locked. The maxSkippedUpdatesLockContention_ doesn't simply count the number of topic updates which skip the table. E.g. if between t1-a and t1-b topic update thread started delta computation 10 times and skipped the table 10 times because ddl2 is holding the lock, it would still be counted as 1 skippedUpdate because it is the same lock operation. If you read the description of catalog_max_lock_skipped_topic_updates it says "This limit only applies to distinct lock operations which block the topic update thread". I think I should update the comment with a more detailed comment. Hope this makes it clearer. -- To view, visit http://gerrit.cloudera.org:8080/17253 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I79e64cdec0e6aa7b597a47851b4b5c5441ca5528 Gerrit-Change-Number: 17253 Gerrit-PatchSet: 4 Gerrit-Owner: Vihang Karajgaonkar <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Quanlong Huang <[email protected]> Gerrit-Reviewer: Vihang Karajgaonkar <[email protected]> Gerrit-Comment-Date: Tue, 06 Apr 2021 23:18:24 +0000 Gerrit-HasComments: Yes
