No it means the opposite of that. I discuss this in the email. The differential graph looks at 0.98.0 and shows what _will_ happen in 0.98.8 (if I understand Gregg's blog post correctly)
> On Nov 14, 2014, at 7:56 PM, Ted Yu <[email protected]> wrote: > > Andrew: > Looking at http://people.apache.org/~apurtell/results-ycsb-0.98.8/f_diff.svg > , Bytes#toShort shows up with +5.88% > Does this mean that Bytes#toShort in 0.98.8 RC1 has higher impact on > performance compared to that of 0.98.0 ? > > Thanks > >> On Fri, Nov 14, 2014 at 7:43 PM, Andrew Purtell <[email protected]> wrote: >> >> Comparing the performance of 0.98.8 RC1 and 0.98.0 using YCSB from >> https://github.com/apurtell/ycsb/tree/new_hbase_client. >> >> In summary, there are minor differences, generally improvements, and this >> test didn't detect performance regression when looking at operation >> latencies. Note 0.98.8RC2 only has HBASE-11698 and HBASE-12478 in addition >> to earlier changes, neither of which will alter these results. >> >> Hardware and Versions >> >> Hadoop 2.4.1 >> HBase 0.98.8-hadoop2 RC1 >> >> 11x EC2 c3.8xlarge: 1 master, 5 slaves, 5 test clients >> 32 cores >> 60 GB RAM >> 2 x 320 GB directly attached SSD >> NameNode: 4 GB heap >> DataNode: 1 GB heap >> Master: 1 GB heap >> RegionServer: 8 GB heap, 24 GB bucket cache offheap engine >> >> Methodology >> >> Setup: >> >> 0. Start cluster >> 1. shell: create "seed", { NAME=>"u", COMPRESSION=>"snappy" } >> 2. YCSB: Preload 100 million rows into table "seed" >> 3. shell: flush "seed" ; compact "seed" >> 4. Wait for compaction to complete >> 5. shell: create_snapshot "seed", "seed_snap" >> 6. shell: disable "seed" >> >> For each test: >> >> 7. shell: clone_snapshot "seed_snap", "test" >> 8. YCSB: Run 5x clients each with -p operationcount=4000000 >> -threads >> 100 -target 20000 (aggregate 100k/ops/sec) >> 9. shell: disable "test" >> 10. shell: drop "test" >> >> I then ran one more workload for each version with the >> lightweight-java-profiler agent installed on one regionserver and generated >> flame graphs from the resulting traces, including the neat new differential >> type. When looking at the differential flame graphs, you'll note the deltas >> are positive. This is the difference between time sampled in the relevant >> call stack on 0.98.0 versus 0.98.8, a positive number means _less_ time was >> spent by 0.98.8 there than 0.98.0. It's also likely that testing with >> higher loads (this test was only with 100k/ops/sec over a 5 slave cluster) >> will present more significant differences. For more information, see >> http://www.brendangregg.com/blog/2014-11-09/differential-flame-graphs.html >> >> Results >> >> YCSB summary: >> >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/ycsb-0.98.0-vs-0.98.8.pdf >> >> Flame Graphs >> 0.98.0 A: >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/a_0.98.0.svg >> 0.98.8 A: >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/a_0.98.8.svg >> Difference: >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/a_diff.svg >> >> 0.98.0 B: >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/b_0.98.0.svg >> 0.98.8 B: >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/b_0.98.8.svg >> Difference: >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/b_diff.svg >> >> 0.98.0 C: >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/c_0.98.0.svg >> 0.98.8 C: >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/c_0.98.8.svg >> Difference: >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/c_diff.svg >> >> 0.98.0 D: >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/d_0.98.0.svg >> 0.98.8 D: >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/d_0.98.8.svg >> Difference: >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/d_diff.svg >> >> 0.98.0 E: >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/e_0.98.0.svg >> 0.98.8 E: >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/e_0.98.8.svg >> Difference: >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/e_diff.svg >> >> 0.98.0 F: >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/f_0.98.0.svg >> 0.98.8 F: >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/f_0.98.8.svg >> Difference: >> http://people.apache.org/~apurtell/results-ycsb-0.98.8/f_diff.svg >> >> >> -- >> Best regards, >> >> - Andy >> >> Problems worthy of attack prove their worth by hitting back. - Piet Hein >> (via Tom White) >>
