[ https://issues.apache.org/jira/browse/HBASE-5001?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13172676#comment-13172676 ]
stack commented on HBASE-5001: ------------------------------ Or, look, Sebastiano and crew made fastutils apache licensed: http://fastutil.dsi.unimi.it/ Has stuff like http://fastutil.dsi.unimi.it/docs/it/unimi/dsi/fastutil/longs/Long2ObjectMap.html (though this not concurrent... would have to sync it) > Improve the performance of block cache keys > ------------------------------------------- > > Key: HBASE-5001 > URL: https://issues.apache.org/jira/browse/HBASE-5001 > Project: HBase > Issue Type: Improvement > Affects Versions: 0.90.4 > Reporter: Jean-Daniel Cryans > Assignee: Lars Hofhansl > Priority: Minor > Fix For: 0.92.0 > > Attachments: 5001-0.92.txt, 5001-v1.txt, 5001-v2.txt > > > Doing a pure random read test on data that's 100% block cache, I see that we > are spending quite some time in getBlockCacheKey: > {quote} > "IPC Server handler 19 on 62023" daemon prio=10 tid=0x00007fe0501ff800 > nid=0x6c87 runnable [0x00007fe0577f6000] > java.lang.Thread.State: RUNNABLE > at java.util.Arrays.copyOf(Arrays.java:2882) > at > java.lang.AbstractStringBuilder.expandCapacity(AbstractStringBuilder.java:100) > at > java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:390) > at java.lang.StringBuilder.append(StringBuilder.java:119) > at > org.apache.hadoop.hbase.io.hfile.HFile.getBlockCacheKey(HFile.java:457) > at > org.apache.hadoop.hbase.io.hfile.HFileReaderV2.readBlock(HFileReaderV2.java:249) > at > org.apache.hadoop.hbase.io.hfile.HFileBlockIndex$BlockIndexReader.seekToDataBlock(HFileBlockIndex.java:209) > at > org.apache.hadoop.hbase.io.hfile.HFileReaderV2$ScannerV2.seekTo(HFileReaderV2.java:521) > at > org.apache.hadoop.hbase.io.hfile.HFileReaderV2$ScannerV2.seekTo(HFileReaderV2.java:536) > at > org.apache.hadoop.hbase.regionserver.StoreFileScanner.seekAtOrAfter(StoreFileScanner.java:178) > at > org.apache.hadoop.hbase.regionserver.StoreFileScanner.seek(StoreFileScanner.java:111) > at > org.apache.hadoop.hbase.regionserver.StoreFileScanner.seekExactly(StoreFileScanner.java:219) > at > org.apache.hadoop.hbase.regionserver.StoreScanner.<init>(StoreScanner.java:80) > at > org.apache.hadoop.hbase.regionserver.Store.getScanner(Store.java:1689) > at > org.apache.hadoop.hbase.regionserver.HRegion$RegionScannerImpl.<init>(HRegion.java:2857) > {quote} > Since the HFile name size is known and the offset is a long, it should be > possible to allocate exactly what we need. Maybe use byte[] as the key and > drop the separator too. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira