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ZhangYao commented on KUDU-749: ------------------------------- Hi, Todd, :) According to your advice I have implemented "seek before" function and make YCSB to get result. I think the improvment is considerable and later I will push my code. YCSB workloada(A zipfian 50/50 update/read workload) with recordcount: 1000000 and operationcount: 10000000 Before change: UPDATE Operations: 5001052 AverageLatency(us): 3.790199142100502 MinLatency(us): 1 MaxLatency(us): 88703 95thPercentileLatency(us): 7 99thPercentileLatency(us):12 After change: UPDATE Operations: 5001749 AverageLatency(us): 229.49272324540877 MinLatency(us): 1 MaxLatency(us): 1796095 95thPercentileLatency(us): 7 99thPercentileLatency(us):14 > Improve performance for zipfian update > -------------------------------------- > > Key: KUDU-749 > URL: https://issues.apache.org/jira/browse/KUDU-749 > Project: Kudu > Issue Type: Improvement > Components: perf, tablet > Affects Versions: Private Beta > Reporter: Todd Lipcon > Priority: Major > Attachments: screenshot-1.png, screenshot-2.png > > > A zipfian 50/50 update/read workload on YCSB gets slower and slower until > it's pretty intolerable (random reads taking 100+ms of CPU). It seems like > all the CPU is spent in DMSIterator::PrepareBatch. We're probably doing > something dumb here - let's look for some low hanging fruit to fix this. -- This message was sent by Atlassian JIRA (v7.6.3#76005)