Spark API example codes

Contains small code snippets used whlie writing code on spark

currently contains

1. Spark Custom Partitioner
   CustomPartitionerTest.scala contains example on how to write a custom partitioner for spark
2. Spakr Querying on real time batches
   InteractiveQuerying.scala describes a example of spark streaming, and executing a query on every batch
3. Spark RDD to DSTream
   RDDtoDStreamExample.scala shows a example to convert a RDD to DStream, union 2 DStreams