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?
rm -fr public/assets
RAILS_ENV=production time bundle exec rake assets:precompile
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 Node took 40 seconds vs 30 seconds using MiniRacer
Edit: this is the command I used:
rm -rf tmp public/assets && time rake assets:precompile
I think there is a way to run compilation in parallel, people with long running times should try that as well as MiniRacer is safe to use from multiple threads (you get an isolate per context)
In our largest app:
system nodejs
real 1m40.834s user 1m29.940s sys 0m11.895s
therubyracer
real 1m14.872s user 1m13.072s sys 0m2.153s
mini_racer
real 0m50.688s user 0m51.122s sys 0m2.688s
A smaller app:
system nodejs
real 0m28.631s user 0m25.277s sys 0m3.931s
therubyracer
real 0m6.153s user 0m5.762s sys 0m0.513s
mini_racer
real 0m6.659s user 0m6.951s sys 0m0.594s
Big old 3.2 app, with therubyracer:
54.21 real 48.66 user 4.48 sys
With mini_racer:
36.70 real 29.15 user 5.14 sys
System nodejs
57.44s user 5.90s system 101% cpu 1:02.34 total
mini_racer
7.08s user 3.48s system 89% cpu 11.824 total
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
I also did a
rm -rf tmp/assetsbefore each run.133s before, 105s after.