Adar Dembo has posted comments on this change. ( http://gerrit.cloudera.org:8080/11111 )
Change subject: KUDU-2525: fix a bug for kudu: scanner return the zero rows ...................................................................... Patch Set 1: (3 comments) Could you reproduce the bug in a kudu-mapreduce unit test? http://gerrit.cloudera.org:8080/#/c/11111/1//COMMIT_MSG Commit Message: http://gerrit.cloudera.org:8080/#/c/11111/1//COMMIT_MSG@7 PS1, Line 7: KUDU-2525: fix a bug for kudu: scanner return the zero rows Rewrite as: KUDU-2525: KuduTableInputFormat may halt before exhausting scan http://gerrit.cloudera.org:8080/#/c/11111/1/java/kudu-mapreduce/src/main/java/org/apache/kudu/mapreduce/KuduTableInputFormat.java File java/kudu-mapreduce/src/main/java/org/apache/kudu/mapreduce/KuduTableInputFormat.java: http://gerrit.cloudera.org:8080/#/c/11111/1/java/kudu-mapreduce/src/main/java/org/apache/kudu/mapreduce/KuduTableInputFormat.java@66 PS1, Line 66: * This input format generates one split per tablet and the only location for each split is that Given that there's one split per tablet, how does this bug manifest? I thought the only time scanner.nextRows() returned an empty RowResultIterator was when the scan ended on one tablet and started up on the next, and the next tablet didn't have any rows. http://gerrit.cloudera.org:8080/#/c/11111/1/java/kudu-mapreduce/src/main/java/org/apache/kudu/mapreduce/KuduTableInputFormat.java@448 PS1, Line 448: // FIXME(qqzhang) the loop is only for the responded empty rows Typically we mark things like this with TODO(...); what's left to do here? Could you instead modify this comment to make it more instructive? You can explain how scanner.nextRows() is allowed to return an empty RowResultIterator, but until scanner.hasMoreRows() returns false, we need to continue iterating on the scanner. -- To view, visit http://gerrit.cloudera.org:8080/11111 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: kudu Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Ifbfdd2efbd281e4d849917664b33e183e180bafd Gerrit-Change-Number: 11111 Gerrit-PatchSet: 1 Gerrit-Owner: zhangqianqiong <[email protected]> Gerrit-Reviewer: Adar Dembo <[email protected]> Gerrit-Reviewer: Kudu Jenkins Gerrit-Comment-Date: Thu, 02 Aug 2018 18:07:14 +0000 Gerrit-HasComments: Yes
