With the rise of big data in recent years, distributed computing engines are emerging one after another. Apache Hadoop is a collection of open-source software utilities that is widely applied on many large websites. The core design of Hadoop comes from the Google MapReduce paper. It is inspired by the map and reduce functions commonly used in functional programming. Map is a higher-order function that applies a given function to each element of a functor, e.g. a list, returning a list of results in the same order. It is often called apply-to-all when considered in functional form. A reduce method performs a summary operation. The MapReduce algorithm is used to classify and process data.
This is a companion discussion topic for the original entry at https://nebula-graph.io/posts/batch-data-importing-to-nebula-graph-via-spark-writer/