Testing and debugging the rmr2 program

Since running a MapReduce program will require a considerable amount of time, varying from a few minutes to several hours, testing and debugging become very important. In this recipe, we will illustrate some techniques you can use to troubleshoot an R MapReduce program.

Getting ready

In this recipe, you should have completed the previous recipe by installing rmr2 into an R environment.

How to do it...

Perform the following steps to test and debug an R MapReduce program:

  1. First, you can configure the backend as local in rmr.options:
    > rmr.options(backend = 'local')
  2. Again, you can execute the number squared MapReduce program mentioned in the previous recipe:
    > b.time = proc.time() 
> small.ints= to.dfs(1:100000) ...

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