Apache Hadoop Common
— Deprecated Properties
In Hadoop 2.0.0 and later, a number of Hadoop and HDFS properties have been deprecated. (The change dates from Hadoop 0.23.1, on which the Beta releases of CDH4 were based). A list of deprecated properties and their replacements can be found at http://archive.cloudera.com/cdh4/cdh/4/hadoop/hadoop-project-dist/hadoop-common/DeprecatedProperties.html.
— Java Virtual Machine (JVM) metrics for logging and garbage collection are cumulative
JVM Metrics for logging and garbage collection are cumulative and not real-time. This causes metrics graphs in tools like Ganglia to trend up even though they're not cause for concern, or creating alerts.
Bug: HADOOP-7866 (unresolved as of 2/21/14)