Rails Dev Speed-Up: From Spork to Zeus

2012-08-16 · 2 min read


Zeus is like Spork on steroids. Beside speeding up tests execution, it also greatly reduces Rails boot up time. Usual development tasks such as server, console, generate execute in about a second!

If you haven't done it yet, you should consider switching from Spork to Zeus.

Vanilla Dev Env

These are execution times for server and console commands on my machine before applying any performance tweaks.

time rails c
rails c  12.03s user 2.56s system 16% cpu 1:09.97 total
time rails s
rails s  11.49s user 2.28s system 35% cpu 39.126 total

Let's try to improve it.

Step 1: Patched Ruby 1.9.3-p194

The following patch for Ruby 1.9.3-p194 by burke incorporates new version of garbage collector that will come with the release of Ruby 2.0. The installation is pretty straightforward, both for rbenv and rvm.

with rbenv

curl https://raw.github.com/gist/1688857/rbenv.sh | sh ; rbenv global 1.9.3-p194-perf

with rvm

rvm get head && rvm reinstall 1.9.3-perf --patch falcon --force-autoconf -j 3

As it's a new version of Ruby, we have to install all gems once again.

gem install bundler
bundle install

Let's check how it improves Rails boot up

time rails c
rails c  4.76s user 1.77s system 78% cpu 8.324 total
time rails s
rails s  4.53s user 1.66s system 74% cpu 8.327 total

Pretty cool. In my case even much faster than declared in the gist 30% time improvement.

Step 2: Zeus

Zeus preloads your Rails environment. It is easier to use that Spork as you don't have to put it as a dependency in Gemfile or to modify any files (e.g. spec_helper). It not only greatly increases tests execution time, but also handles usual development commands (server, console, etc.) The tool was designed to work with new version of garbage collector mentioned above. Check author's screencast to see Zeus in action.

Zeus requires OS X 10.7+ or Linux 2.6.13+ and works with Rails 3.0+ (at the time of writing).

In your project directory:

gem install zeus
zeus init
zeus start

Let's check how Zeus helps with Rails boot up time

time zeus s
zeus s  0.20s user 0.07s system 22% cpu 1.181 total
time zeus c
zeus c  0.20s user 0.07s system 16% cpu 1.715 total



Overall, in my case, Rails server starts approx. 59x faster and Rails console approx. 22x faster than vanilla Ruby/Rails installation. That's quite a change!