MRS deploys and hosts Apache Hadoop clusters in the cloud to provide services featuring high availability and enhanced reliability for big data processing and analysis.
HDFS provides high-throughput data access and is applicable to the processing of large data sets. MRS cluster data is stored in HDFS.
As a programming model that simplifies parallel computing, MapReduce gets its name from two key operations: Map and Reduce. Map divides one task into multiple tasks, and Reduce summarizes their processing results and produces the final analysis result. MRS clusters allow users to submit self-developed MapReduce programs, execute the programs, and obtain the results.
As the resource management system of Hadoop, Yarn manages and schedules resources for applications. MRS uses Yarn to schedule and manage cluster resources.
For details about Hadoop architecture and principles, see http://hadoop.apache.org/docs/stable/index.html.