Ruby on Rails

after playing around more than 6 months, I am now in the position to write some stuff about ruby on rails for new bies. while working in Ruby on Rails, I was really reluctant in the start because of my previously PHP affiliation for more than 3 years. I faced a lot of issues and I will try to bring out those one by one as much as possible, and if any one want to share his/her experience or problems, they are welcome here :)
As soon as, I will learn new things I will keep on post here ;) still need to learn the whole framework yet... a lot of issues and in fact it would be better to say issues always occur because of lack of knowledge. Things are really simple as soon as we know how to handle those.

Deployment Issues:

There are a lot of deployment issues in ruby on rails for a new person which includes mongrels strange behaviour, putting in some additional servers like DRB server for ferret, memcache, monit and capistrano.

1. Capistrano: Start from this wiki page http://wiki.rubyonrails.org/rails/pages/Capistrano I haven't encountered any capistrano problem but just one i.e; making your new directories as symlinks in your public folder or somewhere. Command is really simple but understanding the logic behind it is very important ln -nfs #{shared_path}/user_picture #{release_path}/public/user_picture this command is creating a symlink of user_picture folder. the mistake here that ususally some people do is... they create a folder and commit it with the code as well. this way your symlink command won't work :) So, simple don't remove the folder from the svn you uploaded and commit it again and the problem will be fixed.
2. Mongrel: sometimes your are changing the code and change doesn't appear. it happened to me amny times. project was deployed on the complex architecture of multiple slices. mongrel was going into the zombie state and monit script was unable to do its job as well. It gives the exceptions like Load Error [RAILS_ROOT]/vendor/rails/activesupport/lib/active_support/dependencies.rb:249:in `load_missing_constant', the solution that worked for me was to restart the mongrel_cluster. following command depends on your machine installation: sudo /etc/init.d/mongrel_cluster restart