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jirapos...@reviews.apache.org commented on HBASE-4608: ------------------------------------------------------ ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/2740/#review4732 ----------------------------------------------------------- Only got about halfway through. Will continue to look soon. Overall looking pretty good! src/main/java/org/apache/hadoop/hbase/regionserver/wal/CompressedKeyValue.java <https://reviews.apache.org/r/2740/#comment10459> I'd rename this class to KeyValueCompression or even KVCompression. Then rename readFields to just "read" -- since this is just utility functions, not actually an instance of a compressed keyvalue. src/main/java/org/apache/hadoop/hbase/regionserver/wal/CompressedKeyValue.java <https://reviews.apache.org/r/2740/#comment10460> rather than using keyVal.getRow(), keyVal.getFamily(), keyVal.getQualifer(), you should use the versions of those functions that just return offsets and lengths (eg getKeyOffset, getKeyLength). Then expand the writeCompressed API to take (byte[] buf, int off, int len). Otherwise you're making needless copies/garbage here. src/main/java/org/apache/hadoop/hbase/regionserver/wal/CompressionContext.java <https://reviews.apache.org/r/2740/#comment10461> Since this is so simple, I'd move it to be a static inner class of KVCompression above src/main/java/org/apache/hadoop/hbase/regionserver/wal/Compressor.java <https://reviews.apache.org/r/2740/#comment10462> I think we can merge this with the other class that just has static methods as well. src/main/java/org/apache/hadoop/hbase/regionserver/wal/Compressor.java <https://reviews.apache.org/r/2740/#comment10463> this function requires that the whole log data fit in RAM - not a great assumption src/main/java/org/apache/hadoop/hbase/regionserver/wal/Compressor.java <https://reviews.apache.org/r/2740/#comment10464> why is this split into two if/elses? looks like the top clauses can be combined, as can the bottom clauses src/main/java/org/apache/hadoop/hbase/regionserver/wal/Compressor.java <https://reviews.apache.org/r/2740/#comment10465> switch order of "in" and "offset" here. Perhaps clearer to name this as "uncompressIntoArray"? src/main/java/org/apache/hadoop/hbase/regionserver/wal/Compressor.java <https://reviews.apache.org/r/2740/#comment10467> worth a comment here to explain that the "status" byte actually has the high-order byte of the dictionary entry in the case that it's in the dictionary src/main/java/org/apache/hadoop/hbase/regionserver/wal/Compressor.java <https://reviews.apache.org/r/2740/#comment10466> *un*compressed value, right? - Todd On 2012-01-24 22:29:18, Li Pi wrote: bq. bq. ----------------------------------------------------------- bq. This is an automatically generated e-mail. To reply, visit: bq. https://reviews.apache.org/r/2740/ bq. ----------------------------------------------------------- bq. bq. (Updated 2012-01-24 22:29:18) bq. bq. bq. Review request for hbase, Eli Collins and Todd Lipcon. bq. bq. bq. Summary bq. ------- bq. bq. HLog compression. Has unit tests and a command line tool for compressing/decompressing. bq. bq. bq. This addresses bug HBase-4608. bq. https://issues.apache.org/jira/browse/HBase-4608 bq. bq. bq. Diffs bq. ----- bq. bq. src/main/java/org/apache/hadoop/hbase/HConstants.java 8370ef8 bq. src/main/java/org/apache/hadoop/hbase/regionserver/wal/CompressedKeyValue.java PRE-CREATION bq. src/main/java/org/apache/hadoop/hbase/regionserver/wal/CompressionContext.java PRE-CREATION bq. src/main/java/org/apache/hadoop/hbase/regionserver/wal/Compressor.java PRE-CREATION bq. src/main/java/org/apache/hadoop/hbase/regionserver/wal/HLog.java e46a7a0 bq. src/main/java/org/apache/hadoop/hbase/regionserver/wal/HLogKey.java f067221 bq. src/main/java/org/apache/hadoop/hbase/regionserver/wal/LRUDictionary.java PRE-CREATION bq. src/main/java/org/apache/hadoop/hbase/regionserver/wal/SequenceFileLogReader.java d9cd6de bq. src/main/java/org/apache/hadoop/hbase/regionserver/wal/SequenceFileLogWriter.java cbef70f bq. src/main/java/org/apache/hadoop/hbase/regionserver/wal/WALDictionary.java PRE-CREATION bq. src/main/java/org/apache/hadoop/hbase/regionserver/wal/WALEdit.java e1117ef bq. src/test/java/org/apache/hadoop/hbase/regionserver/wal/TestLRUDictionary.java PRE-CREATION bq. src/test/java/org/apache/hadoop/hbase/regionserver/wal/TestWALReplay.java 59910bf bq. src/test/java/org/apache/hadoop/hbase/regionserver/wal/TestWALReplayCompressed.java PRE-CREATION bq. bq. Diff: https://reviews.apache.org/r/2740/diff bq. bq. bq. Testing bq. ------- bq. bq. bq. Thanks, bq. bq. Li bq. bq. > HLog Compression > ---------------- > > Key: HBASE-4608 > URL: https://issues.apache.org/jira/browse/HBASE-4608 > Project: HBase > Issue Type: New Feature > Reporter: Li Pi > Assignee: Li Pi > Attachments: 4608v1.txt, 4608v5.txt, 4608v6.txt, 4608v7.txt, > 4608v8fixed.txt > > > The current bottleneck to HBase write speed is replicating the WAL appends > across different datanodes. We can speed up this process by compressing the > HLog. Current plan involves using a dictionary to compress table name, region > id, cf name, and possibly other bits of repeated data. Also, HLog format may > be changed in other ways to produce a smaller HLog. -- This message is automatically generated by JIRA. 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