Hadoop

HBase JMX metrics

Tuesday, August 16, 2011
By Steve

HBase exposes several metrics via JMX beans, some of which are similar to the Oracle performance counters recorded by AWR. Actually, they aren’t even *close* to what Oracle provides, but one can hope Below is a simple example of how these can be exposed: Download the jmx command line client jar from http://crawler.archive.org/cmdline-jmxclient/downloads.html Configure... »

Printing hadoop properties

Friday, August 12, 2011
By Steve

The hadoop Configuration class implements the Iterable interface, so you can simply create a default configuration and list all properties, or pass a custom XML configuration file and print the properties from that. Below is a simple example. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 import... »

Getting started with map reduce

Saturday, April 23, 2011
By Steve

Map Reduce is a computer technology algorithm that is built on the age old concept of functional programming.  The goals of functional programming can be simplistically described as: every program returns a value “map” lists of values to functions Map Reduce uses pieces of this methodology, defined as the following: Map – This function... »