Hi,
I am doing some tests I have started Spark in Standalone mode. For simplicity I am using one node only with 8 works and I have 12 cores In spark-env.sh I set this # Options for the daemons used in the standalone deploy mode export SPARK_WORKER_CORES=1 ##, total number of cores to be used by executors by each worker export SPARK_WORKER_MEMORY=1g ##, to set how much total memory workers have to give executors (e.g. 1000m, 2g) the worker export SPARK_WORKER_INSTANCES=8 ##, to set the number of worker processes per node So it is pretty straight forward with 8 works and each worker assigned one core jps|grep Worker 15297 Worker 14794 Worker 15374 Worker 14998 Worker 15198 Worker 15465 Worker 14897 Worker 15099 Worker I start Spark Thrift Server with the following parameters (using standalone mode) ${SPARK_HOME}/sbin/start-thriftserver.sh \ --master spark://50.140.197.217:7077 \ --hiveconf hive.server2.thrift.port=10055 \ --driver-memory 1G \ --num-executors 1 \ --executor-cores 1 \ --executor-memory 1G \ --conf "spark.scheduler.mode=FIFO" \ With one executor allocated 1 core However, I can see both in the OS and UI that it starts with 8 executors, the same number of workers on this node! jps|egrep 'SparkSubmit|CoarseGrainedExecutorBackend'|sort 32711 SparkSubmit 369 CoarseGrainedExecutorBackend 370 CoarseGrainedExecutorBackend 371 CoarseGrainedExecutorBackend 376 CoarseGrainedExecutorBackend 387 CoarseGrainedExecutorBackend 395 CoarseGrainedExecutorBackend 419 CoarseGrainedExecutorBackend 420 CoarseGrainedExecutorBackend I fail to see why this is happening. Nothing else is running Spark wise. The cause? How can I stop STS going and using all available workers? Thanks Dr Mich Talebzadeh LinkedIn * https://www.linkedin.com/profile/view?id=AAEAAAAWh2gBxianrbJd6zP6AcPCCdOABUrV8Pw <https://www.linkedin.com/profile/view?id=AAEAAAAWh2gBxianrbJd6zP6AcPCCdOABUrV8Pw>* http://talebzadehmich.wordpress.com *Disclaimer:* Use it at your own risk. Any and all responsibility for any loss, damage or destruction of data or any other property which may arise from relying on this email's technical content is explicitly disclaimed. The author will in no case be liable for any monetary damages arising from such loss, damage or destruction.