NEW YORK (AP) -- Amazon.com struggled Friday morning to restore computers used by other major websites such as Reddit as an outage stretched beyond 24 hours.
Though better known for selling books, DVDs and other consumer goods, Amazon also rents out space on huge computer servers that run many websites and other online services.
The problems began at an Amazon data center near Dulles Airport outside Washington early Thursday. On Friday morning, Amazon's status page said the recovery effort was making progress, but it couldn't say when all affected computers would be restored.
Most of the sites that were brought down by the outage on Thursday were back up on Friday, but news-sharing site Reddit was still in "emergency read-only mode," and smaller sites were still reporting trouble.
Location-sharing social network Foursquare and HootSuite, which lets users monitor Twitter and other social networks more easily, appeared to have recovered.
Many other companies that use Amazon Web Services, like Netflix Inc. and Zynga Inc., which runs Facebook games, were unscathed by the outage. Amazon has at least one other major U.S. data center that stayed up, in California.
It's not uncommon for Internet services to become inaccessible due to technical problems, sometimes for hours or even days. But the outage is notable because Amazon's servers are so commonly used, meaning many sites went down at once.
Amazon, which had not responded to requests for comment, has not revealed how many companies use its Web services or how many were affected by the outage.
No one knew for sure how many people were inconvenienced, but the services affected are used by millions.
