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https://issues.apache.org/jira/browse/HBASE-16417?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15722264#comment-15722264
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Eshcar Hillel commented on HBASE-16417:
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Attached new benchmarks results.
This time we focus on running experiments with no chunk pool and no mslabs. We
compare the three policies discussed in HBASE-16851: *none* no compaction,
*basic* flattening index, merge only upon flush to disk (HBASE-17081), and
*eager* data compaction.
You may review the results of cluster benchmarks again as they include
experiments with the new *basic* policy (Anastasia's code).
In write-only workload eager improves write amplification by 21%, while basic
improves it by 15%; Basic and eager outperform no compaction by 15% and 25%,
resp.
In read-write workload we show reduction in number of cache accesses and cache
misses by basic and eager w.r.t no compaction. We show modest improvement in
average read latency of basic and eager over none. With slower disks (HDD)
reduction in cache misses will have more positive affect on avg and read tail
latencies.
We experimented with read operation optimization that speculatively scans
memory-only components first and only if the result is incomplete scans both
memory and disk. We ran the mixed workload experiment for none, basic and
eager with and without the optimization.
The optimization improves avg read latency of none and basic by 10% and avg
read latency of eager by 7%. Reduction in cache accesses (70% less accesses),
and cache misses (40%-45% less misses) lead to this improvement.
Finally we ran write-scan workload with size of scan is chosen uniformly from
1-5000. Scan performance of all three policies are comparable with a modest
improvement of basic and eager over none (5%-7%).
> In-Memory MemStore Policy for Flattening and Compactions
> --------------------------------------------------------
>
> Key: HBASE-16417
> URL: https://issues.apache.org/jira/browse/HBASE-16417
> Project: HBase
> Issue Type: Sub-task
> Reporter: Anastasia Braginsky
> Assignee: Eshcar Hillel
> Fix For: 2.0.0
>
> Attachments: HBASE-16417-benchmarkresults-20161101.pdf,
> HBASE-16417-benchmarkresults-20161110.pdf,
> HBASE-16417-benchmarkresults-20161123.pdf,
> HBASE-16417-benchmarkresults-20161205.pdf
>
>
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