First day of LCA 2008
I arrived at linux.conf.au 2008 at the University of Melbourne last night, but didn’t manage to register until this morning. Everything went smoothly as usual except for the friendly (female) registration person addressing me as “Madam”. No doubt it had been a stressful morning.
The conference swag was pretty good this year, the bag is a good size and I can never have too many Redhat caps or Trolltech beer coolers. The t-shirt is also a great design, easily the best of the LCA shirts I have lying around. This one can actually be worn in public without looking too uncool, a considerable achievement. It makes sense what with Melbourne being Australia’s fashion capital.
I kicked off with a presentation by Stuart Middleton as part of the Embedded Mini-conf. Stuart is a type of geek previously unknown to me, a “robotics artist”. Hexapod creations are his speciality. He told us a great story about convincing the Wellcome Trust to give him $2million to build a giant hexapod walking platform for Stelarc. The first version costing $1million twice tore itself apart as soon as it was started because the design “wasn’t quite right.” Such expensive failures can be embarrassing, but apparently this is not too much of a problem because according to Stuart “being artists we can usually come up with some bullshit to explain it”. Very entertaining.
In the second session I stayed with the Embedded Mini-conf for Ben Leslie explaining how to port the OKL4 operating system to a new platform - in this case the Goldfish simulator provided with the Android SDK. I’ve seen Ben present before at SLUG and he always pulls off a slick talk. But he moves fast! This talk was a good introduction to both OKL4 and embedded programming in general.
I then jumped ship to the Security Mini-conf to hear Enno Davids talk on “Self Healing networking”. After a general introduction to network security threats and countermeasures he started talking about the most severe current threat to modern networks- DoS and DDoS attacks. There are currently few effective countermeasures available to deal with the huge botnets that are now being created for profit by well-organized criminal groups. Enno claimed that large botnets can now create aggregate data rates of up to 24Gbps, which is more than the total bandwidth connecting Australia to the rest of the ‘net!
Enno presented some defensive strategies that use ICMP redirect packets to force the botnet zombies to redirect their traffic somewhere else (say 127.0.0.1), but this is not trivial to do and in any case not effective against the largest botnets. He also proposed some small extensions to ICMP that if implemented could help mitigate against such attacks in the future. There was some discussion with the audience of the possibility of distributed responses to DDoS attacks, i.e. calling on friendly networks to help repel an attack. At some point this boils down to “my botnet versus your botnet”, which some wit announced is “coming soon to a Fox channel near you” 
All up a very interesting talk.
After lunch I headed to the Fedora Mini-conf to see Eugene Teo talk on “Writing SystemTap Scripts”. The talk was a good basic introduction to this very useful tool. I attended a similar talk last year at LCA in Sydney, and I’m sorry to say I haven’t actually used SystemTap in the intervening time. But I still think it’s way cool. Eugene also showed us some of the SystemTap scripts he’s been writing, which was fine, but I would have liked it better if he had used the scripts to generate some data suitable for munging into pretty graphs. But that’s just me, I really like graphs.
Next up I checked in on the Community Wireless Mini-conf to hear James Cameron speak on Wireless Design & Testing for the One Laptop Per Child project. James is a resident of somewhere in rural and regional Australia and was sent some XO units to do wireless testing because of the quiet radio environment, similar to areas in the developing world where the XO will be deployed. He also tested an antenna extension gadget that seems to be still in development. James presented some numbers on the achievable range using XO. With two machines 1.5m above the ground, they can communicate as far as 1.6km 95% of the time, which sounds pretty impressive. Unfortunately, due to reasons known only to RF gurus the range drops off significantly when the XOs are closer to the ground. Jim Gettys was in the audience which made for a great Q&A session as he could fill in any gaps in James’ knowledge of the project.
Following afternoon tea I saw Mikko Leppanen talk on “Adventures in Consumer Electronics with GStreamer” as part of the Multimedia Mini-conf. I should probably have spent more time in this mini-conf since I do multimedia stuff for a living now, but that’s just how it worked out. Mikko works for Nokia, specifically writing media playback software for the n810 Internet Tablet. gstreamer is used extensively in the product and Mikko is obviously a big fan, praising gstreamer for being popular, scalable, pluggable and hackable. During question time I asked Mikko how he would compare gstreamer to other multimedia frameworks that he’s used- he commented that the key to a good multimedia framework is a good codec abstraction, and compared to others he’s used such as Helix and the Symbian multimedia framework, gstreamer is clearly superior. He also claimed that Openmax has taken quite a few ideas from gstreamer, which he considers a strong endorsement of gstreamer’s design.
Last up in today’s open-source onslaught was Richard Keech from Redhat talking on “Provisioning Red Hat/Fedora systems using custom builds and Kickstart” as part of the Fedora Mini-conf. Frankly this is not the sort of thing I do on a daily basis, but I like automation and packaging so I had to go. Richard laid out the considerable benefits of his approach- it becomes very easy to reproduce the same machine configuration for testing, development, disaster recovery, etc, but you still get much more flexibility than when creating HD images. During the talk he built, installed (on vmware) and booted a custom build of RHEL. This can be done quickly with a reduced number of packages in the installation.
All up the day was a strong start to what should be another fantastic LCA.
