flink on yarn error "Yarn only has -1 virtual cores available"

大家好，
我安装了Cloudera CDH 6, 然后下载安装flink， 以flink on yarn的方式执行

1. /etc/profile 里增加了变量

export HADOOP_CONF_DIR=/opt/cloudera/parcels/CDH-6.0.0-1.cdh6.0.0.p0.537114/lib/hadoop/etc/hadoop

1. 执行。./yarn-session.sh -n 4 -jm 2048 -tm 2048 -s 3 -nm FlinkOnYarnSession -d -st

结果总是报错：

The number of virtual cores per node were configured with 4 but Yarn only has -1 virtual cores available. Please note that the number of virtual cores is set to the number of task slots by default unless configured in the Flink config with 'yarn.containers.vcores.'

请指导一下，非常感谢！