Blag o' dkam

A Microsoft webserver

dkam@omena ~ $ curl -I http://www.nextbyte.com.au/
HTTP/1.1 200 OK
Server: Microsoft-IIS/5.0

An old favourite. my new filing technique is unstoppable

I was introduced to an excellent website by Ian – howshouldivote.com.au. Nice simple design, simple premise well executed. Answer twenty questions on various issues with multiple choice style, “Agree Strongly” to “Disagree Strongly”. Your results are then compared to candidates in your area ( once you put in your postcode ) and a percentage match is given for the candidates who have answered the survey themselves. You get to see their answers to compare them to yours.

Apparently the Democrats are the closest match ( Not all candidates have completed the survey ) for me – which I suspected.

The questions asked are themselves interesting in predicting what issues are important. This question:

Overall economic growth is less important than reducing the gap between the rich and the poor.

Was answered “Strongly Agree” by the Greens, and “Strongly Disagree” by the Democrats. This one seems to be a trick question – surely we should be focused on making the poorest of us better off, rather than reduce the gap between Rich and Poor? What difference does it make if the gap is big or small? If the gap shrinks, that provides no information about the living standards of the poorest amongst us. Here’s another political fluff question:

The Australian Government should say ‘sorry’ to Indigenous Australians for past injustices.

Saying “Sorry” is a symbolic gesture, it costs nothing, it achieves nothing. It’s astounding that we’re focused on it – surely we should be focused on having a country with no one left behind? A country where we protect and encourage those that need our help? Focusing on a symbolic gesture, rather than focusing on improving the outlook for Indigenous Australians is just another way to ignore the problem and focus on the “Feel Good” stuff.

The domain name bookie.com.au was taken, so I figured I’d carry on the tradition of naming the product like it was a person whose name was Book…. Booko. So you can now find the cheapest place to buy books at booko.com.au.

Found another bug today when one of the remote shops was misbehaving. The open-uri library was throwing exceptions I wasn’t catching.

The original version in the shop model:

def get_pricing(book)
    eval( self.price_function + "(book)" )
end

Replaced by this version:

def get_pricing(book)
  begin
    eval( self.price_function + "(book)" )
  rescue Errno::ECONNRESET => e
    logger.info(">>> Connection Reset checking #{self.name}")
  rescue OpenURI::HTTPError => e
    logger.info(">>> Connection Reset checking #{self.name}")
  end
end

Seems to work quite well.

Looks like Ruby in Leopard has been give the Official treatment, with the latest stable version of Ruby ( plus important patches ) included with the base install. The latest RubyGem is included along with a bunch of useful gems like Rails, Mongrel, Hpricot and Capistrano.

There’s also an /etc/irbrc providing sensible defaults for IRB ( the interactive ruby interpreter ) which requires rubygems for you.

Ruby also comes with DTrace support which is also pretty cool. RubyCocoa is also included and should be fun to play with.

Check out this page for more info on Leopard’s new found Ruby Lovin’.

Seems like Sunday is my blog day. Yesterday I submitted a patch for Ruby’s Open-URI module. It’s a tiny, 2 line patch, which could probably be written better, but it works and scratches an itch of mine. I think this is the first patch I’ve submitted to a software project. Hopefully it won’t languish like another patch to the same module.

Apple is often accused, especially by my hardcore linux mates, of committing the fatal sin of treating the user like an idiot, of reducing the options, or making things simpler than they should be. I’m pretty ambivalent about these claims. A simple example of this is iTunes and it’s desire to manage the on disk layout of your music. I know, some people want to do this themselves, but really, I’ve got better things to do.

I’ll be not at all surprised to hear the same sentiment levelled at Apple’s new backup solution, Time Machine. Time Machine takes a complex, boring, sometimes stressful problem and makes it completely foolproof. There is one main choice to make when setting up Time Machine. Which disk to use for backups. You can optionally exclude directories from being backed-up, and you can be warned when old backups are about to be deleted. That’s it.

I particularly like that you define what not to backup, rather than what should be backed-up. This makes the whole task so much simpler. No guessing which system files should or shouldn’t be backed-up.

If Time Machine is not configured, and you plug in an external drive, it’ll pop up a dialogue box asking you if you’d like to use this disk for backups.

To restore files, you can use the cheesy ‘fly through time’ animated system, or you can just go digging through the backups manually.

If you hard drive fails, you can boot up with the Leopard Install disk and point it at your Time Machine disk and recover your disk to the latest available backup. Brilliant!

The backups made by Time Machine are reasonably space efficient – it makes heavy use of hardlinks and is a variant of a method that I’ve always thought was very clever for it’s simplicity and effectiveness. Each backup is the size of the all the files which have been modified since last backup. Unfortunately, if you work with large files such as photoshop’s or virtual machine disk images, this means that the entire file is backed-up.

There will be nay-sayers of course. There will be those who which to control every aspect of the backup. When to run, how frequently to run. There will be complaints that remote disks should be supported.

But for me, it’s great. It’s taken a task that I have done myself with rsync and cron and made it a no-brainer. A backup solution that my Mum will be able to use. ( I’ll help you set it up mum )

I love reading articles like these, mostly because they deal with issues that I see almost every day in my day job. Adding a new server to your deployment should be as simple as doing a base install and then pointing your configuration management system at it. The hard work should be done once, defining services, their configuration and their relationships.

The operational efficiencies gained from an automated configuration management system should extend beyond growing your current server farm. The time taken to track down bugs and reproduce problems should fall substantially when you know all your servers have the correct configuration. No more diff’ing the config across multiple servers to figure out why one is behaving different to another. No more checking software version numbers across hosts, because sometimes, a host is missed during an upgrade. No more wondering if apache is supposed to be installed on one of your mail servers.

Once your operational staff are relieved of these tedious tasks, their time can be used more effectively in improving aspects of your service. All those tasks that should be done “one day” such as implementing or improving backups, capacity planning or monitoring and reporting of the service can finally get some love.

As we move towards a virtualisation of hardware, automation of provisioning, building and management of servers will become ever more critical. Businesses with advanced operational practices will gain a competitive edge over those organisations who still manually build, configure and maintain their hosts.