Apache spark Monitoring and Instrumentation - vaquarkhan/Apache-Kafka-poc-and-notes GitHub Wiki
Check the Monitoring and Instrumentation API: http://spark.apache.org/docs/latest/monitoring.html
Try hitting: http://:18080/api/v1
Then hit /applications.
That should give you a list of running spark jobs on a given server.
Don't have a Spark cluster up to verify this, but try port 8080.