RHadoop - Running Hadoop MapReduce from R

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Running Hadoop Mapreduce From R. Working with R and Hadoop for large scale data analytics

Running Mapreduce job

m <- mapreduce(InputPath, input.format = 'csv', map = mapFunction, reduce = reduceFunction )

Error: java.lang.RuntimeException: PipeMapRed.waitOutputThreads(): subprocess failed with code 1

Solution

Error seems map not find the file location,
I was trying to reading File from local but by backend configured with Local

rmr.options(backend = "local")

Reading File from Hadoop in R session

f = hdfs.line.reader("/HDFS/GdpData.csv");

Error in .jcheck(silent = TRUE) :
No running JVM detected. Maybe .jinit() would help.

Solution

Run .jinit() to initialize the JVM,

.jinit()

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RHadoop - rJava installtion Error and solution

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Installaing RHadoop package. Working with R and Hadoop for large scale data analytics

Install rJava package from local system

install.packages("/home/bdlnn/Downloads/rJava_0.9-7.tar.gz", repos = NULL)

configure: error: Java interpreter '/usr/lib/jvm/default-java/jre/bin/java' does not work ERROR: configuration failed for package "rJava" * removing "/usr/local/lib/R/site-library/rJava"

Solution

Set JAVA_HOME for R

solai@vm1$ sudo R CMD javareconf JAVA_HOME='/home/bdlnn/Software/jdk1.7.0_79'

dont put '/' in end of JAVA_HOME Path

You can also try the alternate options

solai@vm1$ sudo apt-get install r-cran-rjava

inside R
Sys.setenv(JAVA_HOME='/opt/jdk1.7.0_79/jre')

Related posts :
RHadoop Installation Issues

Working With RHadoop