Hi, all: Sometimes task will fail with exception "About the exception "Received LaunchTask command but executor was null", and I find it is a common problem: https://issues.apache.org/jira/browse/SPARK-13112 https://issues.apache.org/jira/browse/SPARK-13060 I have a question that why should CoarseGrainedExecutorBackend wait for the response of driver? Can we initialize executor in the onStart function after the request to driver? If CoarseGrainedExecutorBackend receive messages like 'LaunchTask' or 'KillTask' which means that it is registered sucessfully.