Author Archives: Clay

I am Clay, you’ll find out more in the entries here…

Debugging HBase Unit Tests

This is likely an obvious process for those who use IDE’s and develop in Maven daily but for those who do operations or otherwise need to work on the JUnit tests in HBase only infrequently, here’s how I worked when submitting a patch for HBASE-16700. First, create your code: Here I was adding a MasterObserver […]

Finding HBase Region Locations

HBase Region Locality HBase provides information on region locality via JMX per region server via the hbase.regionserver.percentFilesLocal. However, there is a challenge when running a multi-tenant environment or doing performance analysis. This percent of files local is for the entire region server but of course each region server can serve regions for multiple tables. And […]

Map/Reduce diff(1)

This has sadly been a draft for years, so time to release it… diff(1) For those who use Unix, you have likely come across two files and wanted to see what was different between the two. Certainly, one can compare size (highly inaccurate), use a hash function (if a strong cryptographic hash, it will be […]


Unless you’ve been living in a cave the last few years, virtualization has been firmly burned in your mind by IT marketing material. In particular, taking massive machines and cutting them up into many smaller virtual machines is the solution converged on by much of the industry. I agree! And, here are my notes on how I moved my group into using CloudStack.
Add a comment

Configuration Files

Many systems have requirements to store configuration parameters. In these systems, a number of choices can be made for how to store that data; sometimes this diversity is painful, however. Choices for storing configuration data are often: Firefox uses and Apple often chooses to use sqlite3 databases1 Python programs often use ConfigParser to process initialization (.ini) […]

Alias does not work in KSH functions

Today, I ran into an aggravating situation. I found that a command which is set-up by sourcing a script with some alias commands in it. But, the script was failing to resolve the alias. I got alias_command: command not found instead of proper resolution. Even more aggravating, running the type built-in on the alias showed that it existed, and was set as expected, but to no success when calling it.
Comments (2)

Accessing Kerberized HDFS via Jython

How to access HDFS on a Kerberos secured Hadoop cluster — code and background!

When do people work?

Ever wonder when people are actually working? It can be hard answering, “when are people at work?” On a distributed team, with many co-workers and the typical corporate dotted-line type relationships, it is even harder! Inevitably communications on schedule shifts and desired schedules go un-communicated. A few years ago, this occurred for folks I worked […]

How I work with IPS repos from the slim_source gate

Oh, how I knew System V packages… Back in the bad old days before ON and slim_source had moved to building only IPS packages, one could pkgadd -d <location> SUNW<package> and easily drop their test code on a machine. Now with the move to IPS packages getting the test code to a machine can be […]

Network Interactions of a Net Booted X86 AI Client

Ever wonder what all the OpenSolaris Automated Installer does and where all the configuration data comes from when net booting an X86 and installing to it?