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Sahil Takiar commented on IMPALA-6705: -------------------------------------- I got bitten by this recently, and it was very confusing. Linking to IMPALA-10137. +1 on fixing this. > TotalNetworkSendTime in query profile is misleading > --------------------------------------------------- > > Key: IMPALA-6705 > URL: https://issues.apache.org/jira/browse/IMPALA-6705 > Project: IMPALA > Issue Type: Bug > Components: Distributed Exec > Affects Versions: Impala 2.5.0, Impala 2.4.0, Impala 2.6.0, Impala 2.7.0, > Impala 2.8.0, Impala 2.9.0, Impala 2.10.0, Impala 2.11.0, Impala 2.12.0 > Reporter: Michael Ho > Priority: Major > Labels: observability > > {{TotalNetworkSendTime}} is actually measuring the time which a fragment > instance execution thread spent waiting for the completion of previous RPC. > This is a combination of: > - network time of sending the RPC payload to the destination > - processing and queuing time in the destination > - network time of sending the RPC response to the originating node > The name of this metric itself is misleading because it gives the impression > that it's the time spent sending the RPC payload to the destination so a > query profile with a high {{TotalNetworkSendTime}} may easily mislead a user > into concluding that there is something wrong with the network. In reality, > the receiving end could be overloaded and it's taking a huge amount of time > to respond to an RPC. > For this metric to be useful, we need to have a breakdown of those 3 > components above. -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-all-unsubscr...@impala.apache.org For additional commands, e-mail: issues-all-h...@impala.apache.org