Category: EmberJS

This is likely the most common type of rebuilds, since it concentrates mostly on the javascript assets under app/ folder and is one of the major concerns for the Core Team to improve the performance.

This kind of rebuilds largely depends on three factors:

• the size of bower_component (the Ember Core Team have plans to largely mitigate this one)
• which preprocessor is being used (libsass vs ruby-sass vs less vs …)
• the amount of CSS

This kind of builds are somewhat costly still, due to how slow available sourceMap Libraries are. The Core Team have a work in progress item with a more V8/JIT friendly sourceMap lib, already showing some very nice improvements.

The build-system assumes a relative fast/performant file system (although, Ember continue to reduce IO related work). It is quite common for a Anti-virus to slow down IO.

Common issues:

• anti-virus scanning of tmp, oftentimes this can be avoided altogether.
• anti-virus on-file-access re-scanning files, oftentimes this can be disabled for the app directory. or ember can be whitelisted.

These sorts of drives are notoriously slow. Although Ember continue to reduce our IO overhead, you will be running at a disadvantage. Oftentimes, a much better alternative is hardware supported full-disk encryption, like on most OSX corporate laptops use. This setup is both reasonably secure, and has negligible impact on performance.

Please run:

and ideally the following should be true (otherwise some upgrades may be required)

• broccoli-funnel should be at ^1.0.1
• broccoli-merge-trees should be at ^1.1.0
• broccoli-persistent-filter should be at ^1.1.6
• broccoli-filter often needs to be replaced with broccoli-persistent-filter (we hope to re-merge the two eventually)
• broccoli-sourcemap-concat should be at ^2.0.2 but will soon be replace by broccoli-concat (we have just re-merged the two)
• broccoli-caching-writer should be at ^2.2.1
• broccoli-concat should be at ^2.0.3
• broccoli-stew should be at ^1.2.0
• likely more…

Up next we should check for old and deprecate plugins

this should no longer be used, rather broccoli-funnel at v1.0.1 should be used

Up next we should look for not-yet-fixed plugins

Well what happened is npm v3 changed the module topology, this coupled with a misbehaving plugin may result in extra files (maybe all of node_modules) being pulled into the build. This is going to be slow.., the solution is to find the offending plugin, and upgrade (or report the issue if it is not yet fixed).

One such plugin is ember-cli-ic-ajax, which has been fixed. So please be sure to upgrade.

Finding such plugins, we can use a series of DEBUG flags, to gain more insight

Despite of all the above scenarios and possible solutions, if the issue still persists, please report an issue in Github with ember-cli project.

Be sure to include:

• npm version
• npm ls (as a gist)
• ideally a reproduction

We can use heimdalljs-logger for logging, which supports the same usage as the de-facto standard debug. Quite often this can be used to quickly discover obviously wrong things.

Usage:

For all logging (this will be very verbose):

For all ember-cli logging:

For all broccoli logging:

For both broccoli and ember-cli logging:

The above patterns will be very verbose. But to make them even more verbose you can set the log level via DEBUG_LEVEL

To make them a bit less verbose, a curated set of performance related logging flags are:

Because many plugins are used repeatedly it may be difficult to see the context for log entries. By default, 3 nodes of context are shown.

To show more (or fewer) lines of context, specify the environment variable DEBUG_DEPTH

[… ConcatWithMaps#782 -> BroccoliMergeTrees#783] means that the log entry occurred in broccoli merge-trees node with id 783, whose parent was a concat with maps node with id 782. These ids are shown in the visualization graph.