Sailesh Mukil has posted comments on this change. Change subject: IMPALA-4764: Add Hedged read metrics ......................................................................
Patch Set 3: (2 comments) http://gerrit.cloudera.org:8080/#/c/6886/3/be/src/runtime/disk-io-mgr-scan-range.cc File be/src/runtime/disk-io-mgr-scan-range.cc: PS3, Line 349: FLAGS_use_hdfs_pread > Why not just always get/update the metrics? It still seems valid to me. I a I agree, however, I did this for perf reasons. The "hdfsGetHedgedReadMetrics" function calls a malloc every time it's invoked. I didn't see any reason why we should have it allocate memory and then free it just to get the same result every time. What do you think? http://gerrit.cloudera.org:8080/#/c/6886/3/common/thrift/metrics.json File common/thrift/metrics.json: Line 563: "description": "The total number of hedged reads won over the life of the process", > , i.e. the number of times hedged reads were faster than the original read Done -- To view, visit http://gerrit.cloudera.org:8080/6886 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: Id4a5d396abb3373d352ad2df8c2272db018114da Gerrit-PatchSet: 3 Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-Owner: Sailesh Mukil <[email protected]> Gerrit-Reviewer: Lars Volker <[email protected]> Gerrit-Reviewer: Matthew Jacobs <[email protected]> Gerrit-Reviewer: Sailesh Mukil <[email protected]> Gerrit-HasComments: Yes
