Many Pies

Many Pies

Monday, July 30, 2007

EC2 pricing

The penny has just dropped with EC2 pricing. You don't pay by the CPU/hour, you pay by the instance/hour. So even if your instance is doing nothing you pay $0.10 per hour. That's $72 per month, which is much more than basic hosting plans. So it's worth it, if you want that much control over your virtual machine.

Wednesday, July 25, 2007


My latest bit of playing around, er, investigation, is with Amazon's EC2 service. I'm thinking of using it for website hosting. I don't expect the website will get much use, but I'm hoping that I can just run up new instances if I need them, and use the simple DNS round robin load balancing to share the load.

From my research there are better ways to load balance, but this should be enough at the moment. Now I just have to pick a suitable distribution and try out my Catalyst application on it.


Monday, July 16, 2007


Darcs is a distributed version control system, a bit like Subversion, RCS, CVS, Visual Source Safe etc. but also different in some ways.

It's taken me quite a while to get my head round it, not because of the lack of introductory material, but because you need to think in a different way to non-distributed source code control.

Because you all tend to have your own repositories my first thought was that changes would clash a lot when you try and combine them. However from my reading
a) they may, but there are ways of resolving them
b) it probably wouldn't happen that much, unless you've got two people working extensively on one file
c) with central repositories you don't worry about that, but you do worry about branching and labeling and other different issues.

One thing that doesn't seem to be addressed is how you deploy your files in something like a web application which doesn't have compilation and the source files are the ones that are used by the "real thing". One way is to use the "darcs dist" command which packages everything up. It's also not clear how you keep two different environments going, e.g. live and QA and dev, where you may have different settings in some files.

The way I'm using on this project (still in stealth mode I'm afraid) is to have a repository on the live site and push patches (read the darcs documentation to see the specific meaning of this word) onto that. That seems to handle both of those problems.

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Friday, July 06, 2007

Installing Catalyst part 3

After much frustration I'm getting somewhere with Catalyst. The source of my frustration was that I hadn't installed libc6-dev onto Ubuntu 6.10, but it took me ages to work that out. Once I did that things moved along nicely.

The instructions that got me to where I am now are:

Type cpan and accept all the defaults, apart from specifying your country at the end, and choosing mirror sites. Pick whatever is appropriate.

Copy to VM
sudo perl cat-install
sudo perl -MCPAN -e 'install Catalyst::Devel'

Thursday, July 05, 2007

Installing Catalyst part 2

Things were going well, until I found a Catalyst plugin needed compiling. The existing system I'm working on was developed under Linux. You can get C compilers for Windows, but I decided to go for the path of least resistance and I'm now downloading an Ubuntu virtual machine.

Wednesday, July 04, 2007

Adventures with Catalyst

So I've got this Catalyst project to pick up. Google analytics tells me that lots of people come here looking for Catalyst Framework. So far they haven't got much to read. Until now...

As the Catalyst Manual says:
One of the frequent problems reported by new users of Catalyst is that it can be extremely time-consuming and difficult to install.

It does go on to explain why though.

It points to instructions at which in turn points to repositories that don't exist any more. However one does, so I start PPM, tell it about the Theoryx5 repository, install it, and go home. More tomorrow...