Build applications through high-level operators.
Spark Streaming brings Spark's language-integrated API to stream processing, letting you write streaming applications the same way you write batch jobs. It supports both Java and Scala.
Stateful exactly-once semantics out of the box.
Spark Streaming recovers both lost work and operator state (e.g. sliding windows) out of the box, without any extra code on your part.
Combine streaming with batch and interactive queries.
By running on Spark, Spark Streaming lets you reuse the same code for batch processing, join streams against historical data, or run ad-hoc queries on stream state. Build powerful interactive applications, not just analytics.
Spark Streaming is developed as part of Apache Spark. It thus gets tested and updated with each Spark release.
If you have questions about the system, ask on the Spark mailing lists.
The Spark Streaming developers welcome contributions. If you'd like to help out, read how to contribute to Spark, and send us a patch!