Really not understanding something here -- I use 5 different CloudFront domains to load some 30+ images on a page, hoping to load them in parallel.

//a.cloudfront.net //b.cloudfront.net //c.cloudfront.net //d.cloudfront.net //e.cloudfront.net|.jpg .jpeg .gif .png .ico .woff .ttf

Still, I get a waterfall indicating that images do not load in parallel (in latest Firefox) -- see attached image.

Any ideas what's happening here?

Comments

wim leers’s picture

Assigned: Unassigned » wim leers
Status: Active » Postponed (maintainer needs more info)

That chart is far too difficult to read. It may be obscuring parallel downloads. I doubt the parallel downloads are not working.

It's much better to use e.g. http://webpagetest.org's connection view. For example, this test for http://tweakers.net: http://www.webpagetest.org/result/120430_0G_44ZCY/1/details/.

Or, for my personal site: http://www.webpagetest.org/result/120430_3M_44ZDD/1/details/. Note how connection 2 is used for resources 2 and 4, but for resource 6, a second connection (connection #3) is opened to load it in parallel.

vacilando’s picture

The initial (long) gray bar means "blocking" in Firebug. Which seems to be indicative of inability to perform (more) requests in parallel.

vacilando’s picture

Status: Postponed (maintainer needs more info) » Active
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See the attached second example, from webpagetest.org.

Not sure what "blocking" from Firebug translates to here.

Does it look right to you? There almost always is "Initial connection" (orange).

wim leers’s picture

Status: Active » Postponed (maintainer needs more info)

That's not the connection view. That's the waterfall view. Please link to the connection view.

vacilando’s picture

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Attaching the connection view. Hmmm, most of them seem to be starting at the same time. Does it look all right to you, too?

wim leers’s picture

Status: Active » Fixed

Those are *all* CloudFront connections? It's quite annoying to always be looking only at a subset of the picture…

That being said, yes, that looks right to me. As you can see, there's only one dark green bar (DNS lookup) per domain name. Then there's 4–6 connections per domain. The images are being loaded in parallel, from the different connections.

Status: Fixed » Closed (fixed)

Automatically closed -- issue fixed for 2 weeks with no activity.