A software glitch slowed Akamai Technologies' servers on 24 May and made it difficult to reach some of its customers' websites, the distributed computing company said.
Some Akamai customers experienced "intermittent performance problems and degradation" for about 90 minutes, between 8am and 9.30am local time.
The problem was caused by a bug in content management software that Akamai customers use to update content on Akamai servers, said Jeff Young, an Akamai spokesman.
Word of the outage surfaced in internet discussion groups, with some suggesting that the company was suffering a denial of service attack. Akamai's service is designed, in part, to thwart such attacks.
The company uses advanced content routing technology and a worldwide network of servers to make sure internet users can quickly access content, despite heavy internet traffic or interruptions in the internet's performance.
Young denied that any "outside interference" was the cause of the trouble, putting the blame squarely on the company's own software.
The tool in question allows Akamai customers to specify how long website content hosted on Akamai's global server network should remain before being updated. Once Akamai staff determined the cause of the problem, they disabled that tool and performance to the customer sites returned to normal, he said.
Akamai declined to comment on how many servers or customers were affected, citing company policy not to name customers. The company is working to restore the content management tool to service and is putting measures in place to prevent future outages.
Paul Roberts writes for IDG News Service