Let's say I have TaskTracker that receives 5 records to process for a single job. When the TaskTracker processses the first record, it will instantiate my Mapper class and execute my setup() function. It will then run the map() method on that record. My question is this : what happens when the map() method has finished processing the first record? I'm guessing it will do one of two things :
1) My cleanup() function will execute. After the cleanup() method has finished, this instance of the Mapper object will be destroyed. When it is time to process the next record, a new Mapper object will be instantiated. Then my setup() method will execute, the map() method will execute, the cleanup() method will execute, and then the Mapper instance will be destroyed. When it is time to process the next record, a new Mapper object will be instantiated. This process will repeat itself until all 5 records have been processed. In other words, my setup() and cleanup() methods will have been executed 5 times each. or 2) When the map() method has finished processing my first record, the Mapper instance will NOT be destroyed. It will be reused for all 5 records. When the map() method has finished processing the last record, my cleanup() method will execute. In other words, my setup() and cleanup() methods will only execute 1 time each. Thanks for the help!
