Hadoop: compress file in HDFS?

Question

I recently set up LZO compression in Hadoop. What is the easiest way to compress a file in HDFS? I want to compress a file and then delete the original. Should I create a

Answer 1

I know this is old thread, but if anyone following this thread (like me) it would be useful to know that any of following 2 methods gives you a tab (\t) character at the end of each line

 hadoop jar $HADOOP_HOME/contrib/streaming/hadoop-streaming-0.20.2-cdh3u2.jar \
      -Dmapred.output.compress=true \
      -Dmapred.compress.map.output=true \
      -Dmapred.output.compression.codec=org.apache.hadoop.io.compress.GzipCodec \
      -Dmapred.reduce.tasks=0 \
      -input  \
      -output $OUTPUT \
      -mapper "cut -f 2"


hadoop jar share/hadoop/tools/lib/hadoop-streaming-2.7.3.jar \
        -Dmapred.reduce.tasks=1 \
        -Dmapred.output.compress=true \
        -Dmapred.compress.map.output=true \
        -Dmapred.output.compression.codec=org.apache.hadoop.io.compress.BZip2Codec \
        -input /input/raw_file \
        -output /archives/ \
        -mapper /bin/cat \
        -reducer /bin/cat \
        -inputformat org.apache.hadoop.mapred.TextInputFormat \
        -outputformat org.apache.hadoop.mapred.TextOutputFormat

From this hadoop-streaming.jar adds x'09' at the end of each line, I found the fix and we need to set following 2 parameters to respecitve delimiter you use (in my case it was ,)

 -Dstream.map.output.field.separator=, \
 -Dmapred.textoutputformat.separator=, \

full command to execute

hadoop jar /jars/hadoop-streaming-2.6.0-cdh5.4.11.jar \
        -Dmapred.reduce.tasks=1 \
        -Dmapred.output.compress=true \
        -Dmapred.compress.map.output=true \
 -Dstream.map.output.field.separator=, \
 -Dmapred.textoutputformat.separator=, \
        -Dmapred.output.compression.codec=org.apache.hadoop.io.compress.Lz4Codec \
        -input file:////home/admin.kopparapu/accenture/File1_PII_Phone_part3.csv \
        -output file:///home/admin.kopparapu/accenture/part3 \
 -mapper /bin/cat \
        -reducer /bin/cat \
        -inputformat org.apache.hadoop.mapred.TextInputFormat \
        -outputformat org.apache.hadoop.mapred.TextOutputFormat