It's what it said on the document. For yarn-standalone mode, it will be the host of where spark AM runs, while for yarn-client mode, it will be the local host you run the cmd.
And what's cmd you run SparkPi ? I think you actually don't need to set sprak.driver.host manually for Yarn mode , SparkContext will handle it for you in Automatically and pass it to AM and Executor to use to connect to Driver. Did you follow the guide in docs/running-on-yarn.md ? Best Regards, Raymond Liu From: Azuryy Yu [mailto:azury...@gmail.com] Sent: Tuesday, December 17, 2013 11:16 AM To: user@spark.incubator.apache.org Subject: About spark.driver.host Hi, I am using spark-0,8,1, and what's the meaning of spark.driver.host? I ran SparkPi failed.(either yarn-standalone or yarn-client) It was 'Hostname or IP address for the driver to listen on.' in the document. but what host the Driver will listen on? the RM on the yarn? if yes, I configured spark.driver.host in the spark-env.sh as resource manager host and port: export SPARK_DAEMON_JAVA_OPTS="-Dspark.driver.host=10.2.8.1 -Dspark.driver.port=8032" but it doesn't work. I find in the log: WARN yarn.ApplicationMaster: Failed to connect to driver at null:null, retrying ... Even if I added these two system env variables to the JAVA_OPTS in the bin/spark-class, it also doen't work, please help. Any inputs are appreciated.