Under normal circumstances the two .axd files load at normal speeds to the browser, i.e. a few hundred milliseconds. I can see them load normally along with all the other page elements by looking at the waterfall chart (network chart) in chrome or another debugging tool.
Occasionally some kind of issue occurs where the two files take about a minute to load. Here are a few other notes:
I’m using the CDN version of ScriptManager, eg:
<asp:scriptreference name="MicrosoftAjax.js" path="http://ajax.microsoft.com/ajax/3.5/MicrosoftAjax.js"></asp:scriptreference>
It looks like others have had a similar issue, but not solved:
WebResource.axd and ScriptResource.axd weird behaviour
WebResource.axd & ScriptResource.axd loading takes more than 1 minute
Question:
Any idea how to figure out what is causing these two files to load so slowly occasionally?
Also, are there any workarounds, such as prebuilding the .axd files or something..?
Maybe hosting http://ajax.microsoft.com/ajax/3.5/MicrosoftAjax.js locally would help?