Posts tagged ‘tech’

Ruby 1.8.6 and ImageMagick 6.3 for Ubuntu 6.06 Dapper 20 Mar 08

We’ve backported some packages useful for Ruby on Rails deployment to the long term support Ubuntu Dapper distro.  They’ve been available for a while but it only just ocurred to us this might be useful to others!

Dapper has Ruby 1.8.4 (though labelled as 1.8.2 in the package list) and ImageMagick 6.2.  Ruby 1.8.4 has some known problems that are fixed in 1.8.6 and the rmagick gem recently updated to version 2, reportedly fixing the memory leaks, but it requires ImageMagick 6.3.

We backported Ruby 1.8.6 p111 and ImageMagick 6.3 from the latest development version of Ubuntu (Hardy Heron) to Dapper.  They’ve been in use on a few boxes and no problems so far.  Feel free to make use of them.  We’ll be backporting any security updates as they come.

General details of the repository are here, with specific information about Ruby 1.8.6 and ImageMagick 6.3 on their own pages.

Ubuntu Hardy Heron is due out in the next few month, which brings a lot of this stuff with it.  Some of you might have the luxury of being able to upgrade to it, but some may need to stick with Dapper for a while - hopefully these packages will help you out.

Posted 20 March 2008 by John Leach ::: add comment

It’s the latency, you see 20 Aug 07

I saw this question about Brightbox on a forum today:

what would be the advantages of hosting with a UK company over a US based company

One simple repercussion of hosting a site for a European audience on an ISP in the USA concerns the Atlantic ocean, which happens to be quite big and that means packets take a long time to traverse it. This results in higher latency. If your ISP is on the West Coast it’s even further away.

Some casual ping testing from a machine in the UK to a number of Rails hosts in the US showed between 95 and 161 millisecond round trip times. With HTTP ping testing I was seeing up to 327ms, which is likely due to the TCP handshake consisting of at least 2 packets before the request is even issued. From the same machine to a Brightbox (different ISPs of course) I saw around 15 milisecond ping RTT and 33 millisecond HTTP.

Average Ping RTT graph (smaller is better)

Ping test

Average HTTP RTT graph (smaller is better)

HTTP ping graph

With HTTP features such as persistent connections you can reduce the impact of the TCP handshake, but with these hosts your European visitors will still see up to 161ms delay before your Rails application even starts processing the request. Fragment caching won’t help you much there. With the new breed of AJAX web applications this is a huge impact on how responsive things will feel to your visitors.

This wasn’t a scientific test with double blind trials, lab coats and conical flasks but it gives you an idea of what a difference 5,500 kilometers makes.

Posted 20 August 2007 by John Leach ::: 1 comment

Why we chose Ubuntu Dapper Drake 3 Aug 07

We’ve had a few beta testers ask about why we chose Ubuntu 6.06 (Dapper Drake) as our primary Xen guest installation, as opposed to one of the more recent releases such as Edgy or Feisty. We chose it primarily because of its support contract.

Ubuntu’s release schedule sees a new version released roughly every 6 months. These releases contain the very latest versions of the software packaged with it and are supported for only 18 months. Once in a while a version is selected as Long Term Support release (LTS) which gets 5 years of server support (3 years for desktop). By support, I mean the Ubuntu team are committed to releasing security upgrades in a timely manner. Dapper was the first LTS version and is support through to June 2011.

If we’d chosen Edgy, security upgrades wouldn’t be available to us after April 2008, forcing all of our Brightboxers to upgrade to Feisty, and so on every 18 months. With the speed that the Rails community jump deployment strategy ships some might say this isn’t a problem, but most installations do need long term stability and Dapper provides that.

There are some issues though, mainly that Dapper’s version of Apache is too old to support the nice proxy balancing stuff that’s used for Mongrel deployments1. To solve this, we chose to use a backported Apache package2. This does mean that we have to commit to backporting all security fixes, but this is trivial compared to all our guest machines needing a full upgrade every 18 months. We still get the Ubuntu team working for us on the other 99.9% of packages.

For our users who like to ride the bleeding edge, they can still upgrade to Feisty themselves if they know what they are doing but for most, this isn’t what Brightbox is all about.

1 A beta tester pointed us in the direction of this bug report requesting an official Apache backport for Dapper. The more people testing these packages and voicing their support, the more likely this might happen.

2 We’re using the backported Apache package provided by kodefoo.com at the moment (http://www.kodefoo.com/2007/2/18/deploying-rails-on-ubuntu-dapper/) but are ready to roll our own if necessary.

Posted 3 August 2007 by John Leach ::: add comment