Configration Problem? (need help to get Spark job executed)

Hi all, I am new to spark and seem to have hit a common newbie obstacle. I have a pretty simple setup and job but I am unable to get past this error when executing a job: TaskSchedulerImpl: Initial job has not accepted any resources; check your cluster UI to ensure that workers are registered

Logstash as a source?

Hi, I plan to have logstash send log events (as key value pairs) to spark streaming using Spark on Cassandra. Being completely fresh to Spark, I have a couple of questions: - is that a good idea at all, or would it be better to put e.g. Kafka in between to handle traffic peeks (IOW: how and