Error in if (file.exists(cmd)) return(cmd) : argument is of length zero

[23mcymcy]

Hi, I try the Rhadoop in my hadoop cluster, but I got a problem. I don't know how to solve this problem. Please help me, thanks.

data<-to.dfs(1:10)
Warning: $HADOOP_HOME is deprecated.

14/11/30 19:12:06 INFO util.NativeCodeLoader: Loaded the native-hadoop library
14/11/30 19:12:06 INFO zlib.ZlibFactory: Successfully loaded & initialized native-zlib library
14/11/30 19:12:06 INFO compress.CodecPool: Got brand-new compressor

result<-mapreduce(input=data,map=function(k,v) cbind(v,v*v))
Warning: $HADOOP_HOME is deprecated.

packageJobJar: [/home/hadoop/hadoop-1.2.1/tmp/hadoop-unjar3993977794382702392/] [] /tmp/streamjob5299922299509802865.jar tmpDir=null
14/11/30 19:14:36 INFO mapred.FileInputFormat: Total input paths to process : 1
14/11/30 19:14:37 INFO streaming.StreamJob: getLocalDirs(): [/home/hadoop/hadoop-1.2.1/tmp/mapred/local]
14/11/30 19:14:37 INFO streaming.StreamJob: Running job: job_201411301740_0002
14/11/30 19:14:37 INFO streaming.StreamJob: To kill this job, run:
14/11/30 19:14:37 INFO streaming.StreamJob: /home/hadoop/hadoop-1.2.1/libexec/../bin/hadoop job -Dmapred.job.tracker=192.168.4.220:9001 -kill job_201411301740_0002
14/11/30 19:14:37 INFO streaming.StreamJob: Tracking URL: http://hadoop001:50030/jobdetails.jsp?jobid=job_201411301740_0002
14/11/30 19:14:38 INFO streaming.StreamJob: map 0% reduce 0%
14/11/30 19:14:43 INFO streaming.StreamJob: map 50% reduce 0%
14/11/30 19:14:44 INFO streaming.StreamJob: map 100% reduce 0%
14/11/30 19:14:46 INFO streaming.StreamJob: map 100% reduce 100%
14/11/30 19:14:46 INFO streaming.StreamJob: Job complete: job_201411301740_0002
14/11/30 19:14:46 INFO streaming.StreamJob: Output: /tmp/file91d6056e965
Error in if (file.exists(cmd)) return(cmd) : argument is of length zero
In addition: Warning message:
closing unused connection 3 (/tmp/RtmpII2l1B/file91d1183597d)
Error in if (file.exists(cmd)) return(cmd) : argument is of length zero

from.dfs(result)
Error in if (file.exists(cmd)) return(cmd) : argument is of length zero
I really do not konw why. Thank you very much for the help.