Archive for August, 2011

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... »

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... »

Today, I had an issue I had seen before, but I can never remember how I fix it. As such, I wanted to document it here. Although rare, periodically an abnormally terminated instance will leave behind a shared memory segment. Since the SGA is attached by key which is the database name and instance_number,... »