Jordan Sissel (semicomplete.com)

Hop on over to the keynav project page and download the new version.

The changelist from the previous announced release is as follows: 20091108: - Added xinerama support. * Default 'start' will now only be fullscreen on your current xinerama display.  read more »

Ruby, like many other dynamic and modern languages, makes it easy for you to do fun stuff like metaprogramming.

Ruby, also like other nice languages, comes with a builtin documentation generator that scans your code for comments and makes them available in html and other formats.

... until you start metaprogramming.

Take a simple example, the Fizzler!  read more »

Lots of changes since the last announced release. Grok should get some more activity now that I'm actually using it in a few places. If you find bugs or have feature requests, please file them on googlecode issue tracker (see below)

The largest changes are:

• we ship with Ruby and C API.
• lots of new testing code.
• we now use tokyocabinet internally instead of bdb.  read more »

With all the TDD (test-driven design) and BDD (behavior-driven design) going around these days, it'd be a shame not to use these tools on monitoring applications.

You might have a boatload of tests that test your application before you roll a new version, but do you use those tests while the application is in production? Can you? Yes!

Let's take an important example of monitoring some complex interaction, like searching google and checking the results. Simple with a mouse, but perhaps complex in code.  read more »

I see this in my server logs quiet often: Oct 23 05:37:48 pww-5 snmpd[23946]: Connection from UDP: [XX.XX.XX.XX]:34650 Oct 23 05:37:48 pww-5 last message repeated 16 times Oct 23 05:37:48 pww-5 snmpd[23946]: Connection from UDP: [XX.XX.XX.XX]:34652 Oct 23 05:37:48 pww-5 last message repeated 24 times Googling points out that in snmpd.conf we should use "dontLogTCPWrappersConnects" - but thet top search results claim that it doesn't work (syntax errors, etc). I tried this: dontLogTCPWrappersConnects This makes an error of: /etc/snmp/snmpd.conf: line 29: Err  read more »

Use the ObjectSpace class to find all ancestors of a given class. class Foo; end class Bar < Foo; end class Baz < Foo; end subclasses = ObjectSpace.each_object(Class).select do |klass| klass.ancestors.include?(Foo) and klass != Foo end # prints "[Baz, Bar]" puts subclasses Of course, you could always override Class#inherited instead, but if you don't want to override methods, the above is a reasonable choice.  read more »

I recently had to do a master failover in mysql to bring up a new mysql master to replace an older one.

The switchover went awry shortly after we told the old master to start slaving off of the new master. The output of 'show slave status' indicated a halt of replication due to foreign key constraints: an auto_increment primary key had a duplicate insert attempt. How did this happen? I'm not sure yet, still digging.

This puzzle made me wonder how we got into that state given that I put the old master in 'read only' mode before doing the switch.  read more »

Got a program that can't setuid but needs to listen on a priviledged port? I was hacking around with Linux's capabilities(7) tonight and came up empty trying to allow a non-priviledged user to bind to port 80 without having to start as root - after all, not everything is capable of setuid on startup, like many java programs.

Speaking of java, if you do setuid, the java hotspot monitor file thing (/tmp/hsperfdata_<user>/<pid>) is in the original user's directory, not the setuid'd user, so you can't jstack reliably. I might be PEBCAKing it, but this is the behavior I observe.  read more »

There's some hot debate around the implications and rightness of service providers to do things like traffic filtering, session hijacking, etc.

I'm not here to talk about that. The data below aims to focus on the technical failures induced by dns hijacking, or dns redirection. I won't bore you with the moral, political, or philosophical discussion around this topic.

Here's a summary if you don't want to read the details:

• DNSBLs probably don't work anymore for Comcast users
• Owned domains (semicomplete.com, google.com, etc) are also subject to hijacking.  read more »

I wanted to test something quickly out in C, but didn't want to write the 5 line of code to do it.  read more »

A project I'm working on has some odd slowness about it. Using ruby-prof, I found that String#scan was consuming most of the time, but ruby-prof didn't tell me where it was coming from. A quick hack that replaced String#scan with my own method showed who was calling it, DateTime.strptime - class String def scan(*args) raise end end I tried using the ruby debugger to break on String#scan, but it didn't seem to work.  read more »

I was working on a new python 2.6 rpm to push at work and started wondering about how to get python eggs to become rpms. Ruby has a gem package called gem2rpm that aids in generating rpms from ruby gems, but there's not really an egg2rpm project.

We're in luck, though. Python's setuptools supports generating rpms by default, it seems.  read more »

I only noticed this now. Perhaps it is old. % dig +noquestion +nostats +nocmd +nocomments www."I wonder if this query will return".com www.I\032wonder\032if\032this\032query\032will\032return.com.  read more »

Hop on over to the xdotool project page and download the new version.

The changelist from the previous announced release is as follows: 20090815: * Incorporate patch from Henning Bekel which adds a new ability to change window properties such as window name, icon name, class, role, etc.  read more »

Just started playing with Munin as a potentially better option than Cacti (hard to automate) for trending. I have about 30 hosts being watched by munin. The munin update job (which fetches and regenerates graphs, etc), by default, runs every 5 minutes. It takes almost 4 minutes to run on a 2.5gHz host. If we add any more things to monitor it's likely that we'll soon overrun the 5 minute interval.

Examining the process, it looks like most of the time is spent generating graphs.  read more »

All DNS servers should respond to invalid domains with advertisement space </sarcasm>, but OpenDNS takes it a step further, by responding to A record queries that aren't possibly valid: % dig +short @208.67.222.222 "When is no-pants-o-clock?" 208.67.219.132 % dig +short @208.67.222.222 "$(dd if=/dev/urandom bs=1 count=30 2> /dev/null)" 208.67.219.132 Good job.  read more »