How to collect Hadoop metrics

This post explores various ways to access metrics from core Hadoop components such as HDFS, MapReduce, and YARN, as well as from ZooKeeper. It discusses collecting metrics using standard development tools like JMX and API calls, as well as specialized tools like Apache Ambari and Cloudera Manager. The post also covers collecting MapReduce counters, Hadoop YARN metrics, and ZooKeeper metrics using both JMX and the four-letter words. Finally, it highlights the importance of having a comprehensive monitoring system that ingests performance metrics from multiple technologies in the data-processing stack.