...www.it-ebooks.info Hadoop Operations Eric Sammer Beijing • Cambridge • Farnham • Köln • Sebastopol • Tokyo www.it-ebooks.info Hadoop Operations by Eric Sammer Copyright © 2012... An Overview Hadoop Metrics Apache Hadoop 0.20.0 and CDH3 (metrics1) Apache Hadoop 0.20.203 and Later, and CDH4 (metrics2) What about SNMP? Health Monitoring Host-Level Checks All Hadoop Processes... sequential operations This minimizes drive seek operations one of the slowest operations a mechanical disk can perform—and results in better performance when doing large streaming I/O operations