tag : mapred

When to Disable Speculative Execution

BackgroundsThis is the link from WikiMedia about what’s Speculative Execution. In Hadoop, the following parameters string are for this settings. And, they are true by default. mapred.map.tasks.specul

MRUnit for Now

Cloudera MRUnit will help with unit testing of mapreduce programming. Below is its support so far. The MapDriver and ReduceDriver support only a single key as input, which can make it more cumbersom