http://pennysmalls.com A blog about Ruby, Rails and other tech. Mostly. Tue, 19 Aug 2008 07:07:25 +0000 http://backend.userland.com/rss092 en It so happens that in our application we need to find the dimensions of many images that do not reside on our rails application server.  I have previously written about how to use the GD library to find image sizes, but this requires fetching the whole file and having it ... http://pennysmalls.com/2008/08/19/find-jpeg-dimensions-fast-in-ruby/ Although Ruby 1.8.7 is not officially recommended yet for Ruby on Rails, it does in fact work fine with Rails 2.1.  And version p22 contains all the latest security fixes. For what it's worth, I can confirm that not only are our apps working well under 1.8.7 (including ferret and over ... http://pennysmalls.com/2008/06/29/rails-on-ruby-187/ Thanks to Óscar Toledo for pointing out to me that my 2004 IOCCC winner is mentioned in this interesting book (in French). It's mentioned on page 53 with some nice commentary. http://pennysmalls.com/2008/06/25/poetic-code/ Rails 2.1.0 has many nice new features, but also it broke our app in some places.  This is what I found: 1. setup_with_fixtures no longer does anything Previously we would use setup_with_fixtures in our tests to do setup actions, but it's not called any more.  Just using plain old setup works for ... http://pennysmalls.com/2008/06/03/rails-210-breakage/ I released a somewhat improved version of slim_attributes as a gem at Rubyforge. It now has better compatibility, and can be just dropped in to provide instant performance improvements. Here is the project homepage. http://pennysmalls.com/2008/04/07/slim-attributes-released-as-a-gem/ I was looking at the implementation of the instantiation of ActiveRecord objects from the database, and the population of the @attributes attribute. There is a method called all_hashes which generates the hashes that are used for the @attributes, so I looked at this. Generating whole hashes for each ... http://pennysmalls.com/2008/04/02/speed-up-mysql-in-rails/ I've spent a considerable amount of time with various tools attempting to figure out why it is that our thin processes (and mongrels before them) grow so egregiously. Typically they reach about 450Mb in a day, after which we restart them via monit. What makes them grow? Well, we ... http://pennysmalls.com/2008/03/23/ruby-leaks-memory/ Thin is getting some attention, so I thought we would give it a try. Installation is just a matter of gem install thin. Run it with something like thin -e production -s 6 That's 6 servers running on 0.0.0.0:3000 to 0.0.0.0:3005 Look at the examples if you need to make a monit recipe. One thing we ... http://pennysmalls.com/2008/03/13/changing-to-thin-from-mongrel/ Sometimes you just don't want to instantiate a bunch of ActiveRecord objects for getting some simple information from the database. You might save on memory and it'll be faster. I made a very simple plugin that enables you to get all the values for one column in a table with ... http://pennysmalls.com/2008/02/25/getting-close-to-the-database-2-columns_as_array-plugin/ Sometimes ActiveRecord wraps your data up too much, and you don't want or need all that convenient but processor-cycle consuming abstraction. We had a case where we wanted to delete nearly 3 million records from our database. The conditions for deletion were a little complex, and writing a single SQL ... http://pennysmalls.com/2008/01/28/getting-close-to-the-database-in-rails/