Help Test MiniRacer.md

MiniRacer https://github.com/discourse/mini_racer is ready for testing.

Can you help out measuring how it improves performance for rake assets:precompile in your app?

• Run:

rm -fr public/assets
RAILS_ENV=production time bundle exec rake assets:precompile

• Edit Gemfile. Remove therubyracer, add:

gem 'execjs', github: 'rails/execjs'
gem 'mini_racer'

• bundle install

• Run:

rm -fr public/assets
RAILS_ENV=production time bundle exec rake assets:precompile

System nodejs

2.65s user 0.84s system 101% cpu 3.436 total

mini_racer

2.61s user 0.82s system 101% cpu 3.380 total

therubyracer:

61.20 real        54.50 user         2.17 sys

mini_racer: 6x faster! :-)

10.30 real         5.26 user         1.50 sys

ruby 2.0.0p481 on OSX 10.11.4

nodejs
9.37s user 1.59s system 99% cpu 11.065 total
9.58s user 1.62s system 99% cpu 11.310 total
9.49s user 1.60s system 99% cpu 11.199 total

mini_racer
9.21s user 1.59s system 99% cpu 10.894 total
9.26s user 1.60s system 99% cpu 10.920 total
9.07s user 1.57s system 99% cpu 10.691 total

Before (therubyracer)

265.78s user 14.32s system 96% cpu 4:50.77 total

After (mini_racer)

263.41s user 13.61s system 97% cpu 4:43.23 total

Rails 4.1.15

using nodejs 4.0.0
76.85s user 19.09s system 86% cpu 1:51.19 total

using mini_racer
14.65s user 6.44s system 68% cpu 30.843 total

🎉

Are you guys deleting the sprockets cache (tmp/assets) between runs? I got several times speed up at first too but then after doing that the speed up was reduced to 25% (still good, but not as unbelievable as I first thought).

Before (therubracer)
21.35s user 6.19s system 96% cpu 28.639 total

After (mini_racer)
4.67s user 1.82s system 84% cpu 7.663 total

Running in a small Rails 5 application (ruby 2.3.1p112) the command:
time RAILS_ENV=production bundle exec rake assets:precompile
(after running rm -rf public/assets tmp/cache/assets)

therubyracer
30.90s user 0.91s system 100% cpu 31.744 total

system node (v4.4.4)
13.35s user 0.99s system 103% cpu 13.913 total

mini_racer
12.33s user 1.02s system 103% cpu 12.858 total

Are you guys deleting the sprockets cache (tmp/assets) between runs? I got several times speed up at first too but then after doing that the speed up was reduced to 25% (still good, but not as unbelievable as I first thought).

I've been using assets:clobber

Results after running rm -rf public/assets tmp/cache/assets before runs:

therubyracer:
67.42s user 3.39s system 95% cpu 1:14.36 total

mini_racer:
55.45s user 3.28s system 97% cpu 59.960 total

Cleared caches and made sure spring wasn't running. Results:

therubyracer: 3m50s user
mini_racer: 1m48s user