| Class | Description | 
|---|---|
| HdfsUtils | |
| RawTextHelper | |
| RawTextSender | A helper program that sends blocks of Kryo-serialized text strings out on a socket at a
 specified rate. | 
| WriteAheadLog | :: DeveloperApi ::
 This abstract class represents a write ahead log (aka journal) that is used by Spark Streaming
 to save the received data (by receivers) and associated metadata to a reliable storage, so that
 they can be recovered after driver failures. | 
| WriteAheadLogRecordHandle | :: DeveloperApi ::
 This abstract class represents a handle that refers to a record written in a
  WriteAheadLog. | 
| WriteAheadLogUtils | A helper class with utility functions related to the WriteAheadLog interface |