spark技术分享MapOutputTrackerWorker — MapOutputTracker for Executors
A MapOutputTrackerWorker is the MapOutputTracker for executors.
MapOutputTrackerWorker uses Java’s thread-safe java.util.concurrent.ConcurrentHashMap for mapStatuses internal cache and any lookup cache miss triggers a fetch from the driver’s MapOutputTrackerMaster.
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Note
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The only difference between MapOutputTrackerWorker and the base abstract class MapOutputTracker is that the mapStatuses internal registry is an instance of the thread-safe java.util.concurrent.ConcurrentHashMap.
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