Sailesh Mukil has posted comments on this change. Change subject: IMPALA-4187: Switch RPC latency metrics to histograms ......................................................................
Patch Set 2: (6 comments) http://gerrit.cloudera.org:8080/#/c/4516/2/be/src/rpc/rpc-trace.cc File be/src/rpc/rpc-trace.cc: PS2, Line 179: int32_t uint32_t? PS2, Line 181: 3 nit: I've previously learned that it's a good practice not to use "magic" constants such as used here, or if it's absolutely necessary, a small comment should explain what the use of said constant is. Is that something that's worth following? http://gerrit.cloudera.org:8080/#/c/4516/2/be/src/util/histogram-metric.h File be/src/util/histogram-metric.h: Line 44: There's no shared state access before this line. Worth locking from here? Line 58: And releasing the lock here? PS2, Line 70: histogram_->Increment(val); On an unrelated note, I looked through the implementation of HdrHistogram and there seems to be use of a lot of atomic operations, but that doesn't make it race-free (which is why it makes sense to use a lock here). Any idea why HdrHistogram is written that way? (Not super important. I was just curious; if you're not sure, we can always revisit it later) PS2, Line 107: boost::scoped_ptr<HdrHistogram> histogram_; I know we had a scoped_ptr vs unique_ptr discussion thread recently, but it doesn't seem like we reached a verdict. It doesn't seem like we intend to move() or release() this pointer, but are we okay with increasing dependency on boost by adding new scoped_ptrs? -- To view, visit http://gerrit.cloudera.org:8080/4516 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: I9ba6d4270dd5676eeeff35ad8d9dc5dcddd95e34 Gerrit-PatchSet: 2 Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-Owner: Henry Robinson <he...@cloudera.com> Gerrit-Reviewer: Henry Robinson <he...@cloudera.com> Gerrit-Reviewer: Juan Yu <j...@cloudera.com> Gerrit-Reviewer: Sailesh Mukil <sail...@cloudera.com> Gerrit-HasComments: Yes
