Amazon.com's main e-commerce site was in trouble yesterday, after it had gone offline on Friday. The trouble also spread to the e-commerce giant's UK-based site.
Between 10:03 am and 10:23 am US Pacific Time, only about 30 percent of visitors managed to enter Amazon.com, according to mobile and Internet management firm Keynote Systems, which tracks Web site performance.
After stabilizing, Amazon.com again wobbled, and its availability dropped to about 68 percent between 10:56 am and 11:09 am, said Shawn White, Keynote's director of external operations.
After that, the site went back to normal and remains that way at press time.
However, the technical gremlins also hit the company's UK storefront on Monday, and the problems there are ongoing.
Availability of the .co.uk site dropped as low as 38 percent for a time, White said.
Amazon said, "Some customers reported intermittent problems accessing Amazon retail Web sites on Monday morning. However, we are working to resolve the issues, and Amazon's web services are not affected."
Even people who managed to enter and browse the sites faced slow performance: While Amazon.com pages typically load in six seconds or less, that average climbed to about 15 seconds during the affected periods, White said.
Gomez, another Web site monitoring firm, puts Amazon's normal average response times between 3 seconds and 8.5 seconds, but that average rose to 14 seconds on Friday and stood in a range of between 2.5 seconds and 14 seconds on Monday.
On Friday, when the availability problems lasted about 3 hours, as well as on Monday, most shoppers having access problems were getting a cryptic error message saying "Http/1.1 Service Unavailable".
This indicates to White that whatever caused the problem proved hard to isolate, making it impossible for the company to configure its system to trigger a more intelligible alert acknowledging the problem in plain English.
White suggested Amazon may have to re-evaluate its testing regime. "The more complex a system is, the more challenging it is to maintain, and a configuration problem here can cause problems somewhere else," he said.
White confirmed Amazon's statement that the company's Amazon Web Services hosted technology services weren't affected by the problems on Friday and Monday.