Strange results from IE8 test locations

I was really pleased to see a Singapore host had been added - luckily performance for our site from Singapore looks pretty good.

However, I noticed a strange issue in the waterfall output from the Singapore IE8 host: the CSS and JS files often (but not always) display “0ms (Request canceled)”, and then appear to be immediately re-requested. This doesn’t seem to impact performance at all - which is odd in itself, since it seems to indicate that the browser canceled and then immediately re-issued the request, since “0ms” is certainly less than a RTT latency.

It turns out that the Dulles IE8 host also exhibits this behavior - hadn’t noticed it before since it doesn’t actually seem to impact performance:

Server logs only seem to show these files being requested once for these page views.

Anyone have any ideas what’s going on?

My theory is that that is how IE8 pre-caches DNS (though it does look really strange when the real requests come right after). I have seen it pretty frequently with IE8.


The Singapore test server seems to have gone. Hope to see it back soon.

Sorry, every now and then you will see agents disappear if they haven’t checked in in a while (and we get alerts so we can work with the partners to get them back online). Any outages are usually pretty short and I’ll send out a notice if we’re expecting a location to be down for an extended period.