Script Scanning slow user Performance

This week I have been investigating slow click to screen response times for a browser based app. Using Fiddler on the client site PCs showed that the majority of time was client rendering/JavaScript execution. Great I thought I could debug this back at base.

However, when I connected my laptop to the test environment response times where much worse. It wasn’t the test environment as fiddler showed that back end performance was fine. My laptop was a higher spec than the client PC so I started up perfmon and observed high CPU as the main cause. However, it was not the Internet explorer process that was consuming the CPU but the McAfee intrusion protection process. Little known to me this was a recent corporate wide download (ok, I probably got the email about it but hey, I get a lot of emails!)

So. the delay was primarily the anti-virus script scanning the JavaScript. Disabled on the clients PC but not on
my laptop Luckily, there is a registry setting that will disable scanning for a particular URL. With that in place I could get around to debugging the JavaScript with IE 8.

Moral of the story check to see if script scanning is enabled on yours abs the clients PC.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s