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SimplyStored and CouchDB

Yesterday I gave a presentation about CouchDB and SimplyStored, our convenience Ruby library, at the Ruby User Group Berlin.

There is a recording of the presentation at ustream.tv.

Frozen Rails 2010

Although Berlin looks a bit like Antarctica right now, I'm really looking forward to travel to Helsinki, Finland for Frozen Rails on May 7th.

Forzen Rails is organized by the guys from the HHLinuxCliub and Kisko Labs. I've met them in Amsterdam back in October and we had a great time. I'm sure Frozen Rails will be too.

Ruby En Rails 2009 Recap

The last past days in Amsterdam for Ruby En Rails 2009 were really great.

I arrived on Thursday and had the chance to discuss a possible security vulnerability in Rails I discovered a while back with Yehuda and Mislav during lunch.

Afterwards we went to the conference dinner and met many very nice people and had a long discussion about voting systems, European vs. American culture, gun laws, and political systems.

Amazon EC2 HighMemory Instances

Very very nice: 34.2 GB RAM and 68.4 GB RAM instances on EC2 

# free -m
             total       used       free     shared    buffers     cached
Mem:         70007       2205      67801          0         28        595
-/+ buffers/cache:       1581      68425
Swap:            0          0          0

Webistrano/Capistrano problem with git

Recently I helped a friend debug a problem when deploying with Webistrano/Capistrano.

He was using a git repository and used SSH keys for authentication. Every time he tried to deploy he got this error: 

 executing locally: "git ls-remote ssh://repo.example.com/git/myproject.git HEAD"
*** Could not save revision: Unable to resolve revision for 'HEAD' on repository 'ssh://repo.example.com/git/myproject.git'.

Ruby on Rails Security

Recently I've been made aware of people inside US Government organizations using my Ruby on Rails Security presentation as an excuse to limit Ruby on Rails adoption and projects inside those organizations.

They mandate that applications in Rails should be redone in Java because of the issues I covered.

Rescue exit

While debugging an unrelated problem in Nanite I've stumbled over this feature in Ruby:

You can rescue the call to Kernel.exit.

Calling exit will just raise a SystemExit exception that can catched as any other. 

#!/usr/bin/env ruby

begin
  exit
rescue SystemExit => e
  puts "somebody wanted to #{e}"
end

puts "after exiting"

This is clearly documented in the RDoc but still I was surprised.

Fragement Caching Tip

We are in the process of testing the new version of MeinProf.de and crossed a very interesting bug.

We are using fragment caching to speed up the serving of the university homepages. So far this is working great and helps a lot with coping with extra load.

The university homepages are served by unis/show.html.erb:

Scotland on Rails 2009 Slides

I know, it is a bit late, but here are my slides from Scotland on Rails:

What to put into Rake tasks

As a consultant for Peritor I often review other peoples code. What I often encounter and always address is custom logic in Rake tasks.

Rake is perfect for automating tasks and making calls into your application from the command line. People often use it for doing maintenance, executing periodic jobs, or starting and stopping services. Nothing wrong with that, this is what Rake in Rails apps is for.

What I resent is having all this logic in the Rakefile, either inline in the task body or as a method in the Rakefile.