Steps involved in a streaming app

Let's look at the steps involved in building a streaming application.

1. The first thing is to create a Streaming context. This can be done as shown in the preceding code example. If you have a SparkContext already available, you can reuse the SparkContext to create a Streaming context as follows:

           val ssc = new StreamingContext(sc, Seconds(5))
           sc = Spark Context reference

   Seconds(5) is the batch duration. This can be specified in milliseconds, seconds, or minutes.

   It is important to note that in local testing, while specifying the master in the configuration object, do not use local or local[1]. This will mean that only a single thread will be used for running the tasks locally.

   Note

   If you are using an input stream based on a receiver, such as, Kafka, Sockets, or Flume, then the single thread will be utilized to run the receiver, leaving you with no threads to process the incoming data. You should always allocate enough cores for your streaming...