Comments on: Doloto: JavaScript download optimizer

By: Steve Souders

Steve Souders — Wed, 07 Oct 2009 16:57:24 +0000

@Dhananjay: For people who have the time and fast (CDN) hosting resources, they should download jQuery and run Doloto to carve it up appropriately. Most sites, however, can’t make this investment of money (CDN) or time. For them, downloading jQuery from a CDN is likely to result in a faster experience. It’s good to have alternatives to match the needs of different web sites.

By: Dhananjay Goyani

Dhananjay Goyani — Wed, 07 Oct 2009 05:38:24 +0000

One question to Steve and Emre.

Microsoft has recently published AJAX and jQuery JS files on its own CDN. For details check ScottGu’s blog. Well, I wonder how DOLOTO is helpful in such scenarios. Aren’t DOLOTO and MS’ CDN arrangement both disagreeing with each other?

By: Ben Livshits

Ben Livshits — Thu, 24 Sep 2009 01:30:15 +0000

Gilberto: thanks for your comment. Doloto currently only runs on Windows. While some users might find that limiting, we often don’t have the development resources to support a more wide-reaching setup. We tried our best to make the tool as open and integratable with other technologies as possible, though.

By: Gilberto

Gilberto — Wed, 16 Sep 2009 13:44:45 +0000

Great idea, unfortunately it’s Microsoft proprietary code that runs only in a Microsoft environment. But, for sure it will inspire the development of an open source alternative written in a language that runs in multiple platforms.

By: Emre Kiciman

Emre Kiciman — Fri, 11 Sep 2009 15:25:53 +0000

JavaScript Multi Lev: Doloto can rewrite any standard Javascript-based web app.

By: Emre Kiciman

Emre Kiciman — Fri, 11 Sep 2009 15:23:42 +0000

V1: Re: site-specific hacks: You’re right that Doloto’s code splitting is specific to whatever workload profile that is fed into Doloto. In the long run, we’d like Doloto to read in multiple executions, so that it can see how the web app behaves across different browsers and user behaviors and use that information to prioritize its code spliting. For now though, what you can do is manually edit the cluster spec that is output by the training, and move the Opera-specific function into the initial cluster, even if Doloto didn’t see its execution during training.

Dhananjay: Since Doloto works as a proxy, it will be able to see dynamically generated Html and Javascript, grab its runtime profile and even rewrite it. You’re right though that you’ll have to do some work to take Doloto’s suggested changes and integrate them back into your code that is dynamically creating these script blocks.

Mike: We have deployed sites with Doloto internally, but unfortunately, nothing external I can point you too right now.

Sunnybear: There are small parts of Doloto’s process that are manual, but Doloto does a lot of the heavy lifting for the developer. The alternative is to analyze and rewrite the whole program by hand! Re: WebOptimizer: it looks like a cool tool, and should be complementary to Doloto. I’d suggest using both for the most benefit.

By: sunnybear

sunnybear — Thu, 10 Sep 2009 10:44:28 +0000

I think Doloto isn’t so promising. It adds overhead for clients scripting, adds traffic (in some cases) and it’s hard to implement it automatically (because it needs statistics and manual configuration).

Here are results for Web Optimizer – http://code.google.com/p/web-optimizator/ – and they are more impressive. So for default CMS installations (usually very simple design and maybe no client side logic) average gain is:
* acceleration 2.25 times,
* +22 in YSlow grade,
* -27% in size,
* -49% in objects.
Here is complete table:
http://code.google.com/p/web-optimizator/wiki/OptimizationResult

By: Javascript Multi Lev

Javascript Multi Lev — Thu, 10 Sep 2009 01:51:34 +0000

very cool & good tip, thank you very much for sharing.

But Doloto is just for .NET and I’m not good at it

By: Mike Belshe

Mike Belshe — Wed, 09 Sep 2009 23:10:58 +0000

Are there any deployed instances of doloto optimized code?

By: Dhananjay Goyani

Dhananjay Goyani — Wed, 09 Sep 2009 10:34:03 +0000

Well, I am not sure if it would be useful for the script blocks attached/added at runtime to the response object.

Anyways, I will give it a try. It looks like sites having separated JS files would get most benefit.