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ramkrishna.s.vasudevan commented on HBASE-20188: ------------------------------------------------ [~Apache9] I did get some more info on the tests. Since my full table scan was for loading the cache i was filtering all the Cells that were coming out of the scan. So this means we will never try to ship anything so there was no need for the switch from pread to STREAM. Since by default any scan will use HDFS pread() now (even if the scan type is DEFAULT) we are seeing that when we do scan region by region evey time there is tcp connection setup and then the read happens in preads where as in STREAM read we don have this connection setup. The blockreader already has the connection in place. That is what the flamegraphs show. > [TESTING] Performance > --------------------- > > Key: HBASE-20188 > URL: https://issues.apache.org/jira/browse/HBASE-20188 > Project: HBase > Issue Type: Umbrella > Components: Performance > Reporter: stack > Assignee: stack > Priority: Blocker > Fix For: 2.0.0 > > Attachments: CAM-CONFIG-V01.patch, HBASE-20188-xac.sh, > HBASE-20188.sh, HBase 2.0 performance evaluation - 8GB(1).pdf, HBase 2.0 > performance evaluation - 8GB.pdf, HBase 2.0 performance evaluation - Basic vs > None_ system settings.pdf, ITBLL2.5B_1.2.7vs2.0.0_cpu.png, > ITBLL2.5B_1.2.7vs2.0.0_gctime.png, ITBLL2.5B_1.2.7vs2.0.0_iops.png, > ITBLL2.5B_1.2.7vs2.0.0_load.png, ITBLL2.5B_1.2.7vs2.0.0_memheap.png, > ITBLL2.5B_1.2.7vs2.0.0_memstore.png, ITBLL2.5B_1.2.7vs2.0.0_ops.png, > ITBLL2.5B_1.2.7vs2.0.0_ops_NOT_summing_regions.png, YCSB_CPU.png, > YCSB_GC_TIME.png, YCSB_IN_MEMORY_COMPACTION=NONE.ops.png, YCSB_MEMSTORE.png, > YCSB_OPs.png, YCSB_in-memory-compaction=NONE.ops.png, YCSB_load.png, > flamegraph-1072.1.svg, flamegraph-1072.2.svg, hbase-env.sh, hbase-site.xml, > hbase-site.xml, hits.png, hits_with_fp_scheduler.png, > lock.127.workloadc.20180402T200918Z.svg, > lock.2.memsize2.c.20180403T160257Z.svg, perregion.png, run_ycsb.sh, > total.png, tree.txt, workloadx, workloadx > > > How does 2.0.0 compare to old versions? Is it faster, slower? There is rumor > that it is much slower, that the problem is the asyncwal writing. Does > in-memory compaction slow us down or speed us up? What happens when you > enable offheaping? > Keep notes here in this umbrella issue. Need to be able to say something > about perf when 2.0.0 ships. -- This message was sent by Atlassian JIRA (v7.6.3#76005)