Minor Description
hdfs dfs -text hit exception when trying to view the compression file created by Linux lz4 tool.
The Hadoop version has HADOOP-11184 "update lz4 to r123", thus it is using LZ4 library in release r123.
Linux lz4 version:
$ /tmp/lz4 -h 2>&1 | head -1 *** LZ4 Compression CLI 64-bits r123, by Yann Collet (Apr 1 2016) ***
Test steps:
$ cat 10rows.txt 001|c1|c2|c3|c4|c5|c6|c7|c8|c9 002|c1|c2|c3|c4|c5|c6|c7|c8|c9 003|c1|c2|c3|c4|c5|c6|c7|c8|c9 004|c1|c2|c3|c4|c5|c6|c7|c8|c9 005|c1|c2|c3|c4|c5|c6|c7|c8|c9 006|c1|c2|c3|c4|c5|c6|c7|c8|c9 007|c1|c2|c3|c4|c5|c6|c7|c8|c9 008|c1|c2|c3|c4|c5|c6|c7|c8|c9 009|c1|c2|c3|c4|c5|c6|c7|c8|c9 010|c1|c2|c3|c4|c5|c6|c7|c8|c9 $ /tmp/lz4 10rows.txt 10rows.txt.r123.lz4 Compressed 310 bytes into 105 bytes ==> 33.87% $ hdfs dfs -put 10rows.txt.r123.lz4 /tmp $ hdfs dfs -text /tmp/10rows.txt.r123.lz4 16/04/01 08:19:07 INFO compress.CodecPool: Got brand-new decompressor [.lz4] Exception in thread "main" java.lang.OutOfMemoryError: Java heap space at org.apache.hadoop.io.compress.BlockDecompressorStream.getCompressedData(BlockDecompressorStream.java:123) at org.apache.hadoop.io.compress.BlockDecompressorStream.decompress(BlockDecompressorStream.java:98) at org.apache.hadoop.io.compress.DecompressorStream.read(DecompressorStream.java:85) at java.io.InputStream.read(InputStream.java:101) at org.apache.hadoop.io.IOUtils.copyBytes(IOUtils.java:85) at org.apache.hadoop.io.IOUtils.copyBytes(IOUtils.java:59) at org.apache.hadoop.io.IOUtils.copyBytes(IOUtils.java:119) at org.apache.hadoop.fs.shell.Display$Cat.printToStdout(Display.java:106) at org.apache.hadoop.fs.shell.Display$Cat.processPath(Display.java:101) at org.apache.hadoop.fs.shell.Command.processPaths(Command.java:317) at org.apache.hadoop.fs.shell.Command.processPathArgument(Command.java:289) at org.apache.hadoop.fs.shell.Command.processArgument(Command.java:271) at org.apache.hadoop.fs.shell.Command.processArguments(Command.java:255) at org.apache.hadoop.fs.shell.FsCommand.processRawArguments(FsCommand.java:118) at org.apache.hadoop.fs.shell.Command.run(Command.java:165) at org.apache.hadoop.fs.FsShell.run(FsShell.java:315) at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70) at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:84) at org.apache.hadoop.fs.FsShell.main(FsShell.java:372)