In Spark, Rob needs to create an accumulator with initial value 3.14 of double type. Please tell him how to do that:

Answer:

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Rob wants to increase the value of this accumulator by 1.1 of double type in each executor. Please him how to do that.

Answer: In the source code for each executor, add the following two lines:

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When Rob implements the join algorithm for joining the phone book and country code lookup table, he needs that each executor can access the code lookup table. Suppose that the lookup table is stored in an RDD named LookupTable1, please tell Rob how to replicate this RDD to all the executors in the driver (master) program.

Answer:

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How to get the broadcasted data in each executor?

Answer:

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For each executor, the Accumulators are -only variables; the broadcast variables are -only variables. Please choose from read or write when you fill in the previous two blanks.