Hi, I've been reviewing how MapOutputTracker works and can't understand the comment [1]:
// Synchronize on the returned array because, on the driver, it gets mutated in place How is this possible since "the returned array" is a local value? I'm stuck and would appreciate help. Thanks! (It also says "Called from executors" [2] so how could the driver be involved?!) [1] https://github.com/apache/spark/blob/master/core/src/main/scala/org/apache/spark/MapOutputTracker.scala#L145 [2] https://github.com/apache/spark/blob/master/core/src/main/scala/org/apache/spark/MapOutputTracker.scala#L133 Pozdrawiam, Jacek Laskowski ---- https://medium.com/@jaceklaskowski/ Mastering Apache Spark 2.0 https://bit.ly/mastering-apache-spark Follow me at https://twitter.com/jaceklaskowski --------------------------------------------------------------------- To unsubscribe e-mail: dev-unsubscr...@spark.apache.org
