Friday, September 19, 2008

A preview: performance tests

I'm headed out the door for some sushi but I thought I'd drop in to give you an idea of what I'm working on for my next blog post. I'm hungry so let's keep this short and sweet: receive interrupt mitigation and its effects on Linux media applications.

In general I'm a big fan of receive interrupt mitigation. I'll trade some delay for a substantial decrease in system CPU time spent servicing interrupts resulting in the ability to handle more calls. I didn't just come to this one day, I've done some tests in the past to verify this.

However, I've never done a large scale test on regular, server class hardware. Usually just Asterisk on an embedded system. It usually works out well. This is why, by default, all ethernet adapters that support NAPI in Linux are enabled in AstLinux by default.

The folks at TransNexus spend a fair amount of time testing OpenSER/Kamailio/OpenSips performance. Today Jim Dalton posted the results of another test to the Kamailio User's mailing list. I replied to his post with so many questions I figured it might be time for me to lab this up myself and test my theories about interrupt handling (in Linux, specifically).

If those brighly colored rolls of fish weren't so distracting and delicious I'd promise to think about all of this over dinner. Unfortunately it will have to wait until tomorrow...

Friday, September 12, 2008

Distro Wars!

I don't like to get into Distro Wars... Nothing is more pathetic than a bunch of FOSS geeks sitting around getting religious about:

- Distros
- Editors
- Star Wars

Ok, ok I started to embrace the stereotype a little towards the end there but if you've ever seen one of these epic battles with your own eyes you just might relate it to Star Wars too.

There are always far more serious things going on in the world and these software hippies sit around and argue about what software to edit ASCII with. Ridiculous.

However, even I will throw down when people bring up the worst idea for a distro ever:


There, I said it. I've officially fired my first shot in a war that has been raging in the Linux community since, oh, 1991 or so.

What's wrong with Fedora, you ask? Of all of the other hundreds of distros, why would I single out Fedora and waste my time writing about it? I'll tell you why:

Much like the iPhone, it's a joke.

I CRINGE. ABSOULTELY CRINGE when I see someone trying to do something serious with Fedora. At this very minute (3am), I am typing a blog post when I should be sleeping. Why you ask? Because I just saw a post on Asterisk-Users with yet another poor soul trying to bring up Asterisk on a Fedora system (Fedora 9). I couldn't possibly sleep knowing the abomination that is Fedora+Asterisk continues.

This is a perfect example to illustrate why Fedora is such a joke. One of the fundamental principles of Linux is reliability. One of the fundamental principles of telephony is reliability. By installing Asterisk on Fedora you are flying in the face of 18 years of Linux and 100+ years of telephony.

Fedora is BLEEDING EDGE. It serves as a test bed for RedHat's next REAL Linux release. How do you feel being a tester for what is sold as a commercial product by a profitable company? Bugs in Fedora are found and fixed quickly...

For six months

You can install Fedora and deal with the usual issues in beta software. Once things finally settle down (after six months or so), you get to upgrade to the next release and start all over again!

Sounds like a great plan for a server or PBX, right?

Hosting companies sell packages based on Fedora. Shame on them. People install PBX systems with Fedora. Double shame on them. The average life span for a PBX is seven years. This means that your Fedora Asterisk system is supported with updates for %7 of the typical PBX lifespan.

CentOS/RHEL/Ubuntu LTS and several other Novell/etc offerings are supported for five years or more.

Granted Fedora has it's place. It makes a nice toy, much like the iPhone. If you want to play with cutting edge Linux, Fedora is for you and it might work on a test system, desktop, laptop, etc.

But please. Please. PLEASE do not install it on a server and don't even think of using it for Asterisk. ANYTHING else will do. Seriously, I don't have a problem with any other distro. Pick one.