In a MapReduce job with 500 map tasks, how many map task attempts will there be?

In a MapReduce job with 500 map tasks, how many map task attempts will there be?
A . It depends on the number of reduces in the job.
B . Between 500 and 1000.
C . At most 500.
D . At least 500.
E . Exactly 500.

Answer: D

Explanation:

From Cloudera Training Course:

Task attempt is a particular instance of an attempt to execute a task

C There will be at least as many task attempts as there are tasks

C If a task attempt fails, another will be started by the JobTracker

C Speculative execution can also result in more task attempts than completed tasks