Csaba Ringhofer has posted comments on this change. ( http://gerrit.cloudera.org:8080/19205 )
Change subject: Long polling to avoid client side wait ...................................................................... Patch Set 6: (3 comments) http://gerrit.cloudera.org:8080/#/c/19205/6//COMMIT_MSG Commit Message: http://gerrit.cloudera.org:8080/#/c/19205/6//COMMIT_MSG@18 PS6, Line 18: This defaults to 100ms. : TODO: Decide if 100ms is reasonable. Maybe keep it turned off for now to avoid side effects? With old clients we can't avoid potentially causing some small regression, as a the long poll may lead to start sleeping in the client just before the query is finished. For clients that subtract the RPC time from the sleep the 100ms looks good. For benchmarking the best would be to bump it above the sleep interval to avoid noise caused by sleeping in the client completely. http://gerrit.cloudera.org:8080/#/c/19205/6//COMMIT_MSG@23 PS6, Line 23: For HS2, this also adds a wait for query completion for the : ExecStatement call. If the the query completes in this time, the : client can avoid a round-trip for the GetOperationStatus call. I don't get it how this is done. TExecuteStatementResp doesn't contain TOperationState - so does the client know wether a GetOperationStatus is needed? http://gerrit.cloudera.org:8080/#/c/19205/6/shell/impala_client.py File shell/impala_client.py: http://gerrit.cloudera.org:8080/#/c/19205/6/shell/impala_client.py@658 PS6, Line 658: sleep_time = min(max(elapsed * 0.01, 0.02), 1.0) Can't this be too frequent if the server doesn't support long poll? The formula leads to polling every 0.02s in the first 2 seconds which may put unnecessary pressure on the coordinator. It could make sense to use the old minimum, as with long poll it would work perfectly and could lead to side effects with older servers. -- To view, visit http://gerrit.cloudera.org:8080/19205 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I72ca595c5dd8a33b936f078f7f7faa5b3f0f337d Gerrit-Change-Number: 19205 Gerrit-PatchSet: 6 Gerrit-Owner: Joe McDonnell <[email protected]> Gerrit-Reviewer: Csaba Ringhofer <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Joe McDonnell <[email protected]> Gerrit-Comment-Date: Mon, 29 Jul 2024 15:05:15 +0000 Gerrit-HasComments: Yes
