[Summary] MapReduce for Software Engineers
TL;DR Processing large-scale data sequentially is slow. MapReduce is a framework for parallel batch processing: you write map and reduce, and the system handles splitting the work, grouping intermediate results, retries, and execution across machines. The Problem Suppose we have a very large set of web server logs and want to count how many times each URL was accessed. On one machine, the logic is simple: Read every log line. Extract the URL....