pyspark.SparkContext.broadcast

SparkContext.broadcast(value)

Broadcast a read-only variable to the cluster, returning a Broadcast object for reading it in distributed functions. The variable will be sent to each cluster only once.

New in version 0.7.0.

Parameters

valueT

value to broadcast to the Spark nodes

Returns

Broadcast

Broadcast object, a read-only variable cached on each machine

Examples

>>> mapping = {1: 10001, 2: 10002}
>>> bc = sc.broadcast(mapping)

>>> rdd = sc.range(5)
>>> rdd2 = rdd.map(lambda i: bc.value[i] if i in bc.value else -1)
>>> rdd2.collect()
[-1, 10001, 10002, -1, -1]

>>> bc.destroy()