Explains when Hadoop Combiners help (or hurt) performance and correctness, with code‑level guidance.

Shows how to instrument MapReduce jobs with Hadoop Counters to track custom metrics during large‑scale processing.

Teaches key partitioning patterns (e.g., partial sorts to specific reducers) to control data flow in MapReduce jobs.

Step‑by‑step setup of a Cloudera VM + Maven project so you can quickly experiment with Hadoop wordcount and beyond.