Administration Archives

Why uninitialized variables are bad (Linux kernel and more)

I've always been an avid hater of uninitialized variables. I'll hunt them down, catch them and beat them to a bloody pulp and then shoot the remains.

Too much, you say? No need for the bat AND the gun, you say? Oh, quite the contrary.

Here is an example of a recently discovered Linux kernel issue. An uninitialized memory segment. The fix is really simple: to initialize it with zeros. This was done in a patch that only adds the following command:


Monitoring according to roles, not category tags

For a while I've had very little to write because I've had very little time to speak. It makes sense when you think of it. :)

We had a lot of changes at $work recently. I've received a new position (as a team manager) but I'm still retaining my "Perl Ninja" title, and I've also had a birthday celebrated at the $office and was given a makeshift rubberband gun, crafted by Tamir Lousky. :)

Another big change (that is the brainchild of Mr. Lousky) is monitoring according to roles and not category tags, which is (at le…

What I would change about App::Genpass

If there is one thing that is more abundant than Hello World programs, it is password generators. Yet, one of the things I could never get right when working on my system administration job (all of them) was comfortable password generation.

There were various methods I've learned from people:

  • The lazy way: "1q2w3e", "qweasd", "qwaszx" and on it goes. A few of my passwords in the old age were exactly these. I've even seen this method used in at least one really big company where I worked. I know many of you might still have some of these pa…

Elegance Fail

Elegance might seem like a lost trait in programming these days, but it is live and vibrant in Perl. A rather large part of the Test namespace is devoted to providing an elegant way to write "run this code, get the result, compare it with this one".

Today I found myself at a loss of an elegant solution to a problem.

I want to run a set of tests. Theoretically I can write each subset of tests as a Role in a test object (there are at ="…

Hello Clarity

For two weeks we've been working hard on defining a rather complex construct of DNS zone files, using multiple servers for multiple domains with cross referencing them and a lot of other complex-sounding terms.

We wrote DNS tests for the zones to make sure all the servers are configured correctly and the general DNS fetching provides correct information. This turned out to be quite difficult.

The original script is 130 lines. This is without taking into account even more testing we wanted. There was a lot of analyzing done which was rather repetitive and the overall code was u…

Perlbal in less than 5 minutes

Perlbal is something I always wanted to learn. A recent DDOS made sure I learned it in an hour or so. Apparently the regular stuff take about 4-5 minutes with it. This post will try to make it shorter.

Suppose you have three servers:
Web1 - webserver number 1 -
Web2 - webserver number 2 -
GW - your gateway server, which you want to use as a reverse proxy for Web1 and Web2.

What you basically need is 2 things:
- Perlbal configured for Web1 and Web2.
- Web1 and Web2's Apache (which is what I'm us…

Testing for Fun and Profit


Yesterday I presented him the idea of tests and showed him Test::More. Yo…

About Sawyer X

user-pic Gots to do the bloggingz