Skype Says Service Outage Was Caused by Massive Restarts - WSJ.com

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In an update to users on Skype's Heartbeat blog, employee Villu Arak said the disruption wasn't because of hackers or any other malicious activity. "The disruption was initiated by a massive restart of our users' computers across the globe within a very short timeframe as they re-booted after receiving a routine software update," he wrote in the message, which was posted early Monday.

"The abnormally high number of restarts affected Skype's network resources. This caused a flood of log-in requests, which, combined with the lack of peer-to-peer network resources, prompted a chain reaction that had a critical impact," he said in the posting.

Skype Says Service Outage Was Caused by Massive Restarts - WSJ.com