Demystifying Asynchronous Actions in Spark

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What if we want to execute 2 actions concurrently on different RDD’s, Spark actions are always synchronous. Like if we perform two actions one after other they always execute in sequentially like one after other.

Let see example

In the above exmaple 2 actions are perform one after other collect and count, both are execute synchronous. So count will always execute after collect will finish. The out of the above code is as follows

Screenshot from 2015-10-21 12:36:04

Now question is if we want to run spark jobs concurrently in async fashion.

So for above question answer is simple apache spark also provide a asyn action for concurrent execution of jobs, Few Asynchronous actions spark provide as follows

collectAsync() -> Returns a future for retrieving all elements of this RDD.
countAsync() -> Returns a future for counting the number of elements in the RDD.
foreachAsync(scala.Function1<T,scala.runtime.BoxedUnit> f) -> Applies a function f to all elements…

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