John, did you try -D option instead of -jobconf, I had -D option in my code, I changed it with -jobconf, this is what I get:
... ... Options: -input <path> DFS input file(s) for the Map step -output <path> DFS output directory for the Reduce step -mapper <cmd|JavaClassName> The streaming command to run -combiner <JavaClassName> Combiner has to be a Java class -reducer <cmd|JavaClassName> The streaming command to run -file <file> File/dir to be shipped in the Job jar file -inputformat TextInputFormat(default)|SequenceFileAsTextInputFormat|JavaClassName Optional. -outputformat TextOutputFormat(default)|JavaClassName Optional. -partitioner JavaClassName Optional. -numReduceTasks <num> Optional. -inputreader <spec> Optional. -cmdenv <n>=<v> Optional. Pass env.var to streaming commands -mapdebug <path> Optional. To run this script when a map task fails -reducedebug <path> Optional. To run this script when a reduce task fails -verbose Generic options supported are -conf <configuration file> specify an application configuration file -D <property=value> use value for given property -fs <local|namenode:port> specify a namenode -jt <local|jobtracker:port> specify a job tracker -files <comma separated list of files> specify comma separated files to be copied to the map reduce cluster -libjars <comma separated list of jars> specify comma separated jar files to include in the classpath. -archives <comma separated list of archives> specify comma separated archives to be unarchived on the compute machines. The general command line syntax is bin/hadoop command [genericOptions] [commandOptions] For more details about these options: Use $HADOOP_HOME/bin/hadoop jar build/hadoop-streaming.jar -info I think -jobconf is not used in v.0.19 . 2009/2/18 S D <sd.codewarr...@gmail.com> > I'm having trouble overriding the maximum number of map tasks that run on a > given machine in my cluster. The default value of > mapred.tasktracker.map.tasks.maximum is set to 2 in hadoop-default.xml. > When > running my job I passed > > -jobconf mapred.tasktracker.map.tasks.maximum=1 > > to limit map tasks to one per machine but each machine was still allocated > 2 > map tasks (simultaneously). The only way I was able to guarantee a maximum > of one map task per machine was to change the value of the property in > hadoop-site.xml. This is unsatisfactory since I'll often be changing the > maximum on a per job basis. Any hints? > > On a different note, when I attempt to pass params via -D I get a usage > message; when I use -jobconf the command goes through (and works in the > case > of mapred.reduce.tasks=0 for example) but I get a deprecation warning). > > Thanks, > John > -- M. Raşit ÖZDAŞ
