Tim Armstrong has posted comments on this change. Change subject: IMPALA-5199: prevent hang on empty row batch exchange ......................................................................
Patch Set 2: I think there is a fundamental problem with the "closed streams cache" mechanism and long-running queries with limits in the middle of the plan though - IMPALA-3990 - which can happen even not under load. I think that's the bug you're describing. I guess this change makes IMPALA-3990 possible when 0 rows are sent. To me, it seems better to make behaviour consistent and avoid this hang even if adds another presumably rare case to IMPALA-3990. I don't think we've seen IMPALA-3990 in practice. I can see the argument though for just leaving this alone given the hang also seems to be rare. What do you think? -- To view, visit http://gerrit.cloudera.org:8080/8005 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: Ib370ebe44e3bb34d3f0fb9f05aa6386eb91c8645 Gerrit-PatchSet: 2 Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-Owner: Tim Armstrong <tarmstr...@cloudera.com> Gerrit-Reviewer: Sailesh Mukil <sail...@cloudera.com> Gerrit-Reviewer: Tim Armstrong <tarmstr...@cloudera.com> Gerrit-HasComments: No
