Category Archives: Linux

How To Interview

Posted on October 18, 2011 by Gaius

One of the things I do at my present job is interview candidates for my team, and occasionally other teams too. I estimate I’ve seen ~150 people over the last 5 years. Of those very few that I do say … Continue reading →

Posted in Business, Linux, Oracle, Python | Tagged , , , | 1 Comment

Failing Gracefully

Posted on September 22, 2011 by Gaius

Let’s say you have a high-performance system, operating beyond it’s design capacity already, and the workload is increasing. What would you like it to do? Keep running, but slow down. This is the default behaviour for most applications, as in, … Continue reading →

Posted in Business, Linux, Oracle | Leave a comment

The Importance of Representative Simulation

Posted on September 14, 2011 by Gaius

By now, most serious DBAs and SAs should have a basic grasp of queuing theory concepts such as offered load, even if not actually using the maths everyday. A busy system may have thousands of processes, each waiting for their … Continue reading →

Posted in Linux, Oracle | 2 Comments

Segmentation Faults, TAP and Eclipse

Posted on September 9, 2011 by Gaius

This is quite a neat trick. Consider: Referencing that NULL pointer obviously crashes straight away with a terse segmentation fault: By simply linking it with libSegFault, which seems to be documented only very informally, but comes with glibc: Of course … Continue reading →

Posted in C++, Emacs, Linux, Ocaml, Operation Foothold | Tagged , , , , , , | 3 Comments

A Matter of Priorities

Posted on July 22, 2011 by Gaius

I recently helped migrate some internal services, including DNS, from conventional Linux boxes to Infoblox devices. Nifty bits of kit, but one issue occured during the migration: a RAC node eviction! This is an interesting scenario as it illustrates something … Continue reading →

Posted in Linux, Oracle | Leave a comment

Is Virtualization Worth It?

Posted on July 19, 2011 by Gaius

Before planning any project, the first thing I like to do is ask what outcome are we trying to achieve here? A case in point is virtualization, the holy grail of IT du jour. A virtualized infrastructure is not a … Continue reading →

Posted in Business, Linux, Oracle | 2 Comments

Extprocs in OCaml

Posted on July 12, 2011 by Gaius

An external procedure or EXTPROC is a technique for calling C or other native code from SQL in Oracle. Why might you want to do this? To interface to a 3rd party system for which there is only a C … Continue reading →

Posted in Linux, Ocaml, Operation Foothold, Oracle | 2 Comments

Unix diagnostic tools for DBAs

Posted on May 27, 2011 by Gaius

When a server application I am supporting starts to misbehave, there are a few tools I reach for to perform a quick diagnosis. Some of these are little known to DBAs who usually work within the database, so here is … Continue reading →

Posted in Linux, Oracle, Shareplex | 5 Comments

New MTL

Posted on April 21, 2011 by Gaius

Just rebuilt my Debian VM with latest-everything, having to tweak some code from MTL 1 to MTL 2. Seems straightforward enough, but the proof of the pudding, as they say, is in the eating…

Posted in Haskell, Linux | Leave a comment

Calling Unix libraries from OCaml

Posted on April 14, 2011 by Gaius

(This is something I did in December but have only just gotten round to posting about) The OCaml Unix module provides many of the system calls needed for day-to-day work, but occasionally there is one that is only available in … Continue reading →

Posted in Linux, Ocaml, Shareplex | 2 Comments