[PDF] [PDF] Using Apache Hadoop - Cloudera documentation
26 mai 2015 · The Hortonworks Data Platform consists of the essential set of Apache Hadoop projects including MapReduce, Hadoop Distributed File System (
26 mai 2015 · The Hortonworks Data Platform consists of the essential set of Apache Hadoop projects including MapReduce, Hadoop Distributed File System (
Clicking on the link brings one to a Hadoop Map/Reduce Tutorial (http://hadoop apache org/core/docs/current/mapred_tutorial html) explaining the Map/Reduce
docs.hortonworks.com hadoop-[VERSION]/share/hadoop/ mapreduce export YARN_EXAMPLES=$YARN_HOME/share/hadoop/mapreduce $YARN_HOME $YARN_HOME yarn jar $YARN_EXAMPLES/hadoop-mapreduce-examples-2.1.0-beta.jar An example program must be given as the first argument.
Valid program names are:
aggregatewordcount: An Aggregate-based map/reduce program that counts the words in the input files. aggregatewordhist: An Aggregate-based map/reduce program that computes the histogram of the words in the input files. bbp: A map/reduce program that uses Bailey-Borwein-Plouffe to compute exact digits of Pi. dbcount: An example job that counts the pageview counts from a database. distbbp: A map/reduce program that uses a BBP-type formula to compute exact bits of Pi. grep: A map/reduce program that counts the matches of a regex in the input. join: A job that effects a join over sorted, equally partitioned datasets. multifilewc: A job that counts words from several files. pentomino: A map/reduce tile-laying program that finds solutions to pentomino problems. pi: A map/reduce program that estimates Pi using a quasi-Monte Carlo method. randomtextwriter: A map/reduce program that writes 10GB of random textual data per node. randomwriter: A map/reduce program that writes 10GB of random data per node. secondarysort: An example defining a secondary sort to the reduce. sort: A map/reduce program that sorts the data written by the random writer. sudoku: A sudoku solver. teragen: Generate data for the terasort. terasort: Run the terasort. teravalidate: Check the results of the terasort. wordcount: A map/reduce program that counts the words in the input files. wordmean: A map/reduce program that counts the average length of the words in the input files. wordmedian: A map/reduce program that counts the median length of the words in the input files. wordstandarddeviation: A map/reduce program that counts the standard deviation of the length of the words in the input files. pi terasortTestDFSIO yarn jar $YARN_EXAMPLES/hadoop-mapreduce-examples-2.1.0-beta.jar pi 16 100000
13/10/14 20:10:01 INFO mapreduce.Job: map 0% reduce 0%
13/10/14 20:10:08 INFO mapreduce.Job: map 25% reduce 0%
13/10/14 20:10:16 INFO mapreduce.Job: map 56% reduce 0%
13/10/14 20:10:17 INFO mapreduce.Job: map 100% reduce 0%
13/10/14 20:10:17 INFO mapreduce.Job: map 100% reduce 100%
13/10/14 20:10:17 INFO mapreduce.Job: Job job_1381790835497_0003 completed
successfully
13/10/14 20:10:17 INFO mapreduce.Job: Counters: 44
File System Counters
FILE: Number of bytes read=358
FILE: Number of bytes written=1365080
FILE: Number of read operations=0
FILE: Number of large read operations=0
FILE: Number of write operations=0
HDFS: Number of bytes read=4214
HDFS: Number of bytes written=215
HDFS: Number of read operations=67
HDFS: Number of large read operations=0
HDFS: Number of write operations=3
Job Counters
Launched map tasks=16
Launched reduce tasks=1
Data-local map tasks=14
Rack-local map tasks=2
Total time spent by all maps in occupied slots (ms)=174725
Total time spent by all reduces in occupied slots
(ms)=7294
Map-Reduce Framework
Map input records=16
Map output records=32
Map output bytes=288
Map output materialized bytes=448
Input split bytes=2326
Combine input records=0
Combine output records=0
Reduce input groups=2
Reduce shuffle bytes=448
Reduce input records=32
Reduce output records=0
Spilled Records=64
Shuffled Maps =16
Failed Shuffles=0
Merged Map outputs=16
GC time elapsed (ms)=195
CPU time spent (ms)=7740
Physical memory (bytes) snapshot=6143696896
Virtual memory (bytes) snapshot=23140454400
Total committed heap usage (bytes)=4240769024
Shuffle Errors
BAD_ID=0
CONNECTION=0
IO_ERROR=0
WRONG_LENGTH=0
WRONG_MAP=0
WRONG_REDUCE=0
File Input Format Counters
Bytes Read=1888
File Output Format Counters
Bytes Written=97
Job Finished in 20.854 seconds
Estimated value of Pi is 3.14127500000000000000
pi terasort application_138... job_138... n0:8042 teragen yarn jar $YARN_EXAMPLES/hadoop-mapreduce-examples-2.1.0-beta.jar teragen
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[PDF] MapReduce Tutorial - Apache Hadoop - The Apache Software