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Gaps in internet explorer tests - Printable Version

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Gaps in internet explorer tests - nilskuhn - 05-22-2015 01:39 AM


I see gaps in waterfalls with tests in internet explorer I don't understand:

If these gaps between DNS lookup and connection initialization or between connection/ssl-handshake and ttfb would appear in follow-up resource requests I would assume the browser performs DNS pre-resolution and/or TCP pre-connection. But in initial (HTML-)request?

I don't understand these gaps.
Is that a bug in rendering of wpt waterfall and dns lookup or connection initialization last longer than bars in waterfall chart look like?
Or is it a problem in wpt or browser software on agent machines and browser is busy in these gaps? But there is nothing eye-catching in cpu utilization...

Best regards, Nils

RE: Gaps in internet explorer tests - pmeenan - 05-22-2015 05:04 AM

You can capture a tcpdump and look at the packets to verify but last time I did that for IE 11 the gaps were real and I have no idea what IE is doing in that time.

RE: Gaps in internet explorer tests - WebsiteSpeedExperts - 05-24-2015 07:48 AM

IE is... well IE. It is often derided for doing things it shouldn't and it is pretty much a law unto itself.

My best guess was that there were other processes being kicked off in the background (looking at the CPU utilisation graphs).