Register UDF duration runtime

Hi , I meeting some issue when I try to read from some string coming from web service as an UDF string and register. Here is the exception. java.lang.ClassCastException: cannot assign instance of scala.collection.immutable.List$SerializationProxy to field

How to submit some code segment to existing SparkContext

Hi, Is there any way to submit some code segment to the existing SparkContext? Just like a web backend, send some user code to the Spark to run, but the initial SparkContext takes time, just want to execute some code or Spark Sql, and get the result quickly. Thanks, Bin