Add way to limit default # of cores used by applications on standalone mode

Also documents the spark.deploy.spreadOut option.

1 files changed, 10 insertions, 0 deletions

diff --git a/docs/spark-standalone.md b/docs/spark-standalone.md
index c851833a18..f47d41f966 100644
--- a/docs/spark-standalone.md
+++ b/docs/spark-standalone.md
@@ -167,6 +167,16 @@ val conf = new SparkConf()
 val sc = new SparkContext(conf)
 {% endhighlight %}
 
+In addition, you can configure `spark.deploy.defaultCores` on the cluster master process to change the
+default for applications that don't set `spark.cores.max` to something less than infinite.
+Do this by adding the following to `conf/spark-env.sh`:
+
+{% highlight bash %}
+export SPARK_JAVA_OPTS="-Dspark.deploy.defaultCores=<value>"
+{% endhighlight %}
+
+This is useful on shared clusters where users might not have configured a maximum number of cores
+individually.
 
 # Monitoring and Logging