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Lars Hofhansl commented on HBASE-9969: -------------------------------------- Tested again without performing a major compaction. In my scenario I have 10m rows with 5 columns each. Ends up being only three regions and only that last one has more than one store file (4 in this case). With that I still did not see any improvement. Re: HBASE-9778, it's still not immediately clear there how to optimize the cases mentioned there (many small KVs) while keeping other optimizations (for example for large KVs, where the likelihood is high that a call to next() will land us unnecessarily in the next block). Anything that will bring HBase's CPU consumption down is a win. Unless all data is in the cache I would expect us always being CPU bound, that is not always true (with SSDs for example). > Improve KeyValueHeap using loser tree > ------------------------------------- > > Key: HBASE-9969 > URL: https://issues.apache.org/jira/browse/HBASE-9969 > Project: HBase > Issue Type: Improvement > Components: Performance, regionserver > Reporter: Chao Shi > Assignee: Chao Shi > Fix For: 0.98.0, 0.96.1 > > Attachments: hbase-9969-v2.patch, hbase-9969.patch, hbase-9969.patch, > kvheap-benchmark.png, kvheap-benchmark.txt > > > LoserTree is the better data structure than binary heap. It saves half of the > comparisons on each next(), though the time complexity is on O(logN). > Currently A scan or get will go through two KeyValueHeaps, one is merging KVs > read from multiple HFiles in a single store, the other is merging results > from multiple stores. This patch should improve the both cases whenever CPU > is the bottleneck (e.g. scan with filter over cached blocks, HBASE-9811). > All of the optimization work is done in KeyValueHeap and does not change its > public interfaces. The new code looks more cleaner and simpler to understand. -- This message was sent by Atlassian JIRA (v6.1#6144)