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Todd Lipcon commented on HDFS-13702: ------------------------------------ Here are some perf results based on a 180GB teravalidate on a small cluster, as well as a 1GB teravalidate on LocalJobRunner (against a remote HDFS) {code} 3.0.x original ------------------------------------ Avg map: 18sec CPU time spent (ms) 2,208,950 GC time elapsed (ms) 68,153 Performance counter stats for './run-validate.sh' (5 runs): 22357.081985 task-clock (msec) # 2.688 CPUs utilized ( +- 6.78% ) 21,573 context-switches # 0.965 K/sec ( +- 2.58% ) 1,300 cpu-migrations # 0.058 K/sec ( +- 4.82% ) 425,146 page-faults # 0.019 M/sec ( +- 4.52% ) 63,809,409,850 cycles # 2.854 GHz ( +- 6.56% ) 66,580,182,677 instructions # 1.04 insn per cycle ( +- 2.28% ) 13,489,574,848 branches # 603.369 M/sec ( +- 4.58% ) 158,670,595 branch-misses # 1.18% of all branches ( +- 0.35% ) 8.317048233 seconds time elapsed ( +- 0.10% ) 3.0.x patched: -------------------------------------------------------------------------------- Avg map time: 14sec CPU time spent (ms) 1,750,180 GC time elapsed (ms) 42,468 Performance counter stats for './run-validate.sh' (5 runs): 14466.559412 task-clock (msec) # 2.006 CPUs utilized ( +- 3.18% ) 21,666 context-switches # 0.001 M/sec ( +- 0.55% ) 1,180 cpu-migrations # 0.082 K/sec ( +- 1.91% ) 234,159 page-faults # 0.016 M/sec ( +- 0.60% ) 41,793,452,250 cycles # 2.889 GHz ( +- 2.77% ) 55,219,815,925 instructions # 1.32 insn per cycle ( +- 1.67% ) 9,837,238,534 branches # 679.998 M/sec ( +- 2.57% ) 161,071,903 branch-misses # 1.64% of all branches ( +- 0.62% ) 7.210730451 seconds time elapsed ( +- 0.25% ) {code} > HTrace hooks taking 10-15% CPU in DFS client when disabled > ---------------------------------------------------------- > > Key: HDFS-13702 > URL: https://issues.apache.org/jira/browse/HDFS-13702 > Project: Hadoop HDFS > Issue Type: Bug > Components: performance > Affects Versions: 3.0.0 > Reporter: Todd Lipcon > Assignee: Todd Lipcon > Priority: Major > Attachments: hdfs-13702.patch > > > I am seeing DFSClient.newReaderTraceScope take ~15% CPU in a teravalidate > workload even when HTrace is disabled. This is because it stringifies several > integers. We should avoid all allocation and stringification when htrace is > disabled. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org