Huaisi Xu has posted comments on this change. Change subject: IMPALA-4740: Add option to use hdfsPread() for HDFS hedged reads ......................................................................
Patch Set 2: > The HDFS-5776 JIRA mentions that it's implemented for the pread() > code path, but it's not that clear. If you look at the code it's > very clear that it only kicks in on the pread() code path: > > https://github.com/apache/hadoop/search?utf8=%E2%9C%93&q=isHedgedReadsEnabled I may be wrong again (as always), hdfspread is not pread. from https://github.com/apache/hadoop/blob/f67237cbe7bc48a1b9088e990800b37529f1db2a/hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfs/hdfs.c#L1426, you can see hdfspread() invokes read(), and hdfsread() calls read() as well, and in turn read() calls pread() as you can see in the link you just quoted. So this new gflag is essentially ignored? What did I miss here? -- To view, visit http://gerrit.cloudera.org:8080/5635 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: Iecc8b12aa20cbfe08f4ef6a08a191e49709d9525 Gerrit-PatchSet: 2 Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-Owner: Matthew Jacobs <[email protected]> Gerrit-Reviewer: Dan Hecht <[email protected]> Gerrit-Reviewer: Huaisi Xu <[email protected]> Gerrit-Reviewer: Internal Jenkins Gerrit-Reviewer: Matthew Jacobs <[email protected]> Gerrit-Reviewer: Tim Armstrong <[email protected]> Gerrit-HasComments: No
