They don’t call it Black Friday for nothing. And as shoppers increasingly use websites and mobile apps to do their shopping—even as they brave the crowds in brick-and-mortar stores—some retailers are finding it hard to handle demands.

While content delivery networks (CDNs) have made it possible to push static content out closer to Web and mobile shoppers and reduce overall traffic hitting e-commerce sites, the load on the sites is still causing some to buckle and break, albeit briefly.

Even Hewlett-Packard has gotten a bit of a bloody nose as HP Shopping went down around midday Eastern Time. And Best Buy’s website went offline briefly—though by noon those who had left their browsers pointed at the website were switched back to the electronics store. The trials and tribulations of major retailers’ websites are being live-blogged by David Jones of Dynatrace, an application performance management subsidiary of Compuware.