LCA09: Day 2 : Tuesday

2nd day of 2009 I was again at the Sysadmin Miniconf all day.

The first talk was by Matt Moore on how he scaled a hosting solution for a charity ( $20 of donations over 6 weeks ) website and ensured ( in the face of some big problems and not huge budget ) reliability of the site ( where outages cost $1000 per minute during peak ).

Next there were a couple to IPv6 talks from Glen Turner and Angus Lees. Angus’ talk covered how he and a couple of other people were working towards getting a AAAA record for . They have spent the last year or so working towards it. The most interesting bit was they were doing survey ( using a web-bug on 1/1000 user ) to see how many users of google could access a URL that had both a A and AAAA record. His stats found that when both records were presented 0.238% of users used the AAAA URL and 0.09% broke. The 0.238% was increasing during the period when he tested ( late 2008 ). He also found that access ( ie route path optimisation ) was around 150ms worse than the ipv4 path. Overall he seemed to think google could go live with ipv6 records in 1-2 years.

Glen’s talk was a bit more general with some intro to ipv6 and the way ipv4 addresses were running out. But he also addressed the concerns that in 3-5 years when ipv4 address run out ipv6 won’t be ready and ISPs will start implementing NAT solutions which will break the end-to-end connectivity of the Internet. He also thought that large access providers would try and use this to try and extract a greater control and share of the revenue from the Internet ( ie not just access but a share of the profits from the end sites in return for proving eyeballs).

After Lunch Devdas Bhagat covered database backed authoritative DNS servers. His company hosts a high number of domains and needs very high performance. He did a good comparison and work though of how they tried bind and eventually moved the PowerDNS ( pdns) . They paid a developer to enhance some of the paths in the system and that latest releases ( a RC with pdns although Devdas has been running it for months ) get some 40,000 q/s on standard hardware ( which exceeds the gold standard commercial product from nominum ( do do do do do ) ).

Steve Ellis then covered trac with some concentration on using trac ( and similar solutions ) better to tie in documentation, tickets and workflow better rather than just keeping them all separate.

The Lightning talks covered ( SAGE-AU , Time management, DKIM , Computer Room disaster stories and a quick plug from a linux based router vendor ). I especially liked the DKIM intro presentation which reminded me of the old format people used to sign Usenet Control messages.

The session covered Spam, Roland Turner from Boxsentry covered the product his company uses to reduce false positives. He also announced that his company was allowing people to freely talk to his companies system ( probably via a spamassian plugin ) up to 100,000 queries/day. See .

Peter Chubb then did some general spam filtering advice.

Last up we had a BOF talking about what software and hardware people were using on their site. A good chance for people to catch the names of tools others were using and ideas for what they could look at. One thing I was interested in was that only around 5 out of the people in the room were actually using puppet on their site.