1 files changed, 67 insertions, 0 deletions
diff --git a/R/README.md b/R/README.md
new file mode 100644
index 0000000000..a6970e39b5
--- /dev/null
+++ b/R/README.md
@@ -0,0 +1,67 @@
+# R on Spark
+
+SparkR is an R package that provides a light-weight frontend to use Spark from R.
+
+### SparkR development
+
+#### Build Spark
+
+Build Spark with [Maven](http://spark.apache.org/docs/latest/building-spark.html#building-with-buildmvn) and include the `-PsparkR` profile to build the R package. For example to use the default Hadoop versions you can run
+```
+  build/mvn -DskipTests -Psparkr package
+```
+
+#### Running sparkR
+
+You can start using SparkR by launching the SparkR shell with
+
+    ./bin/sparkR
+
+The `sparkR` script automatically creates a SparkContext with Spark by default in
+local mode. To specify the Spark master of a cluster for the automatically created
+SparkContext, you can run
+
+    ./bin/sparkR --master "local[2]"
+
+To set other options like driver memory, executor memory etc. you can pass in the [spark-submit](http://spark.apache.org/docs/latest/submitting-applications.html) arguments to `./bin/sparkR`
+
+#### Using SparkR from RStudio
+
+If you wish to use SparkR from RStudio or other R frontends you will need to set some environment variables which point SparkR to your Spark installation. For example 
+```
+# Set this to where Spark is installed
+Sys.setenv(SPARK_HOME="/Users/shivaram/spark")
+# This line loads SparkR from the installed directory
+.libPaths(c(file.path(Sys.getenv("SPARK_HOME"), "R", "lib"), .libPaths()))
+library(SparkR)
+sc <- sparkR.init(master="local")
+```
+
+#### Making changes to SparkR
+
+The [instructions](https://cwiki.apache.org/confluence/display/SPARK/Contributing+to+Spark) for making contributions to Spark also apply to SparkR.
+If you only make R file changes (i.e. no Scala changes) then you can just re-install the R package using `R/install-dev.sh` and test your changes.
+Once you have made your changes, please include unit tests for them and run existing unit tests using the `run-tests.sh` script as described below. 
+    
+#### Generating documentation
+
+The SparkR documentation (Rd files and HTML files) are not a part of the source repository. To generate them you can run the script `R/create-docs.sh`. This script uses `devtools` and `knitr` to generate the docs and these packages need to be installed on the machine before using the script.
+    
+### Examples, Unit tests
+
+SparkR comes with several sample programs in the `examples/src/main/r` directory.
+To run one of them, use `./bin/sparkR <filename> <args>`. For example:
+
+    ./bin/sparkR examples/src/main/r/pi.R local[2]
+
+You can also run the unit-tests for SparkR by running (you need to install the [testthat](http://cran.r-project.org/web/packages/testthat/index.html) package first):
+
+    R -e 'install.packages("testthat", repos="http://cran.us.r-project.org")'
+    ./R/run-tests.sh
+
+### Running on YARN
+The `./bin/spark-submit` and `./bin/sparkR` can also be used to submit jobs to YARN clusters. You will need to set YARN conf dir before doing so. For example on CDH you can run
+```
+export YARN_CONF_DIR=/etc/hadoop/conf
+./bin/spark-submit --master yarn examples/src/main/r/pi.R 4
+```