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Hudson commented on HBASE-13109: -------------------------------- FAILURE: Integrated in HBase-1.1 #247 (See [https://builds.apache.org/job/HBase-1.1/247/]) HBASE-13109 Make better SEEK vs SKIP decisions during scanning. (larsh: rev f5020e9c1a98727cb100f24294df50072d599bf8) * hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/HFileScanner.java * hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/HFileReaderV2.java * hbase-client/src/main/java/org/apache/hadoop/hbase/client/Scan.java * hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/ExplicitColumnTracker.java * hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StoreFileScanner.java * hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StoreScanner.java * hbase-server/src/main/java/org/apache/hadoop/hbase/io/HalfStoreFileReader.java * hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/BlockWithScanInfo.java * hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestQueryMatcher.java * hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestExplicitColumnTracker.java * hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/NonLazyKeyValueScanner.java * hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/KeyValueScanner.java * hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestBlocksRead.java * hbase-common/src/main/java/org/apache/hadoop/hbase/KeyValue.java * hbase-common/src/main/java/org/apache/hadoop/hbase/HConstants.java * hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/KeyValueHeap.java * hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/ScanQueryMatcher.java * hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/HFileBlockIndex.java > Make better SEEK vs SKIP decisions during scanning > -------------------------------------------------- > > Key: HBASE-13109 > URL: https://issues.apache.org/jira/browse/HBASE-13109 > Project: HBase > Issue Type: Improvement > Reporter: Lars Hofhansl > Assignee: Lars Hofhansl > Fix For: 2.0.0, 1.0.1, 1.1.0, 0.98.12 > > Attachments: 13109-0.98-v4.txt, 13109-trunk-v2.txt, > 13109-trunk-v3.txt, 13109-trunk-v4.txt, 13109-trunk-v5.txt, 13109-trunk.txt, > nextIndexKVChange_new.patch > > > I'm re-purposing this issue to add a heuristic as to when to SEEK and when to > SKIP Cells. This has come up in various issues, and I think I have a way to > finally fix this now. HBASE-9778, HBASE-12311, and friends are related. > --- Old description --- > This is a continuation of HBASE-9778. > We've seen a scenario of a very slow scan over a region using a timerange > that happens to fall after the ts of any Cell in the region. > Turns out we spend a lot of time seeking. > Tested with a 5 column table, and the scan is 5x faster when the timerange > falls before all Cells' ts. > We can use the lookahead hint introduced in HBASE-9778 to do opportunistic > SKIPing before we actually seek. -- This message was sent by Atlassian JIRA (v6.3.4#6332)