Correct Answer: File system Counters
Hadoop maintains built-in counters for every job that reports several metrics for each job. For example, there are built-in counters for the number of bytes and records processed, which helps to assure the expected amount of input was consumed and the expected amount of output was produced, etc.
Built-in counters are of three types:
- Mapreduce Task Counters
- File system counters
- Job Counters
To understand built-in counters in Hadoop, you can join Hadoop Certification.
You can watch this YouTube tutorial on Hadoop to get started: