Grunt tasks are slow in yeoman application - ruby-on-rails

Question

I have an angular project build with yeoman, talking to a rails api backend.
Everything works fine, except that grunt tasks are very slow.
When I run grunt server --verbose:
Execution Time (2014-01-15 13:37:55 UTC)
loading tasks 14.3s ▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 26%
server 1ms 0%
preprocess:multifile 11ms 0%
clean:server 13ms 0%
concurrent:server 34.3s ▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 63%
autoprefixer 1ms 0%
autoprefixer:dist 369ms ▇ 1%
connect:livereload 17ms 0%
watch 5.8s ▇▇▇▇▇▇▇▇▇ 11%
Total 54.8s
Some of my Gruntfile:
'use strict';
module.exports = function (grunt) {
require('time-grunt')(grunt);
require('load-grunt-tasks')(grunt);
require('time-grunt')(grunt);
grunt.initConfig({
...
});
grunt.loadNpmTasks('grunt-preprocess');
grunt.registerTask('server', function (target) {
if (target === 'dist') {
return grunt.task.run(['build', 'connect:dist:keepalive']);
}
grunt.task.run([
'preprocess:multifile',
'clean:server',
'concurrent:server',
'autoprefixer',
'connect:livereload',
'watch'
]);
});
grunt.registerTask('test', [
'clean:server',
'concurrent:test',
'autoprefixer',
'connect:test'
//'karma'
]);
grunt.registerTask('build', [
'preprocess:multifile',
'clean:dist',
'useminPrepare',
'concurrent:dist',
'autoprefixer',
'concat',
'copy:dist',
'cdnify',
'ngmin',
'cssmin',
'uglify',
'rev',
'usemin'
]);
grunt.registerTask('default', [
'jshint',
'test',
'build'
]);
};
Size of project:
vagrant#vm ~code/myapp/app/scripts
$> find -name "*.js" | xargs cat | wc -l
10209
I am running on MacOS 10.8 with i7 processor, 16GB ram, SSD... It is normal that is takes so long ? What makes the grunt task (and especially "loading tasks") so slow ?
Note: I am ssh'd inside a vagrant machine and running the grunt commands from there. If I run the grunt command on my native system, it's much faster (loading tasks takes 1.6s instead of 14.3).
So the shared filesystem might be an issue. But why...

Answer 1

I had exactly same problem with Vagrant and Yeomans angular-generator. After running grunt serve it took almost 30 seconds to compile sass, restart server etc.
I already used NFS but it was still slow. Then I tried jit-grunt, just-in-time grunt loader. I replaced load-grunt-tasks with jit-grunt and everything is now a lot faster.
Here's a good article about JIT-Grunt:
https://medium.com/written-in-code/ced193c2900b

Answer 2

I am using grunt inside a Vagrant virtualbox. (ubuntu 12.04). My native files are on my host machine (OSx). Because the grunt tasks are io-intensive, and they are run through file sharing, this make them quite slow.
This can be improved by adding nfs to Vagrant (http://docs.vagrantup.com/v2/synced-folders/nfs.html). This will make Vagrant share files with nfs instead of the default Vagrant file sharing. It will be a bit faster, but not much.
For comparison, on my machine:
For running the subtask loading grunt tasks
natively: 1.2s
with nfs: 4s
vagrant file sharing: 16s
If only a specific task is taking a lot of time, this specific task might be the problem. To troubleshoot, use time-grunt: https://npmjs.org/package/time-grunt.

Answer 3

I've had issues as well, and have found:
nospawn: true
To be the fastest option. I went from ~20s to ~1s to concat, minify, and uglify JS.

Answer 4

I had the same problem with Yeoman's ngbp generator and Vagrant. Even with nfs, a simple change on a template took about 30s to be seen in the browser.
Using jit-grunt caused time to be reduced to 10s. After using spawn:false, even though there was no reduction at the first load, changes took less than 1s (0.086s) to propagate to the browser! (Yes!)
The changes I've made to Gruntfile.js:
I commented all the grunt.loadNpmTasks but grunt.loadNpmTasks('grunt-contrib-watch') [That's because of a task rename ngbp does later on];
I added require('jit-grunt')(grunt); after grunt.loadNpmTasks('grunt-contrib-watch');
I added spawn: false to delta: { options: {livereload: true, spawn: false} ...}.