July 26, 2012 -- Twitter had a widespread outage today, the second in six weeks.
At around 11:20 a.m. ET, Twitter users started to see their streams come to a screeching halt and were not able to send 140-character messages. The service did not come back online until 1:25 p.m. ET, Twitter confirmed.
Twitter attributed the outage to an issue at its data centers.
"Data centers are designed to be redundant: when one system fails (as everything does at one time or another), a parallel system takes over. What was noteworthy about today's outage was the coincidental failure of two parallel systems at nearly the same time," Mazen Rawashdeh, Twitter's VP for Engineering, wrote on the company blog.
Twitter used to be infamous for such periodic outages and the appearance of the "fail whale" error page. It has substantially improved its server capacity in the past two years. Users today didn't see the "fail whale" page; instead, the site didn't load.
As of February, the Pew Internet and American Life Project reported that "some 15 percent of online adults use Twitter, and 8 percent do so on a typical day."
Twitter is expected to see increased traffic from the upcoming Olympic games. NBC and others have partnered with the social media service to share news, links and videos.
"I wish I could say that today's outage could be explained by the Olympics or even a cascading bug. Instead, it was due to this infrastructural double-whammy," Rawashdeh said. "We are investing aggressively in our systems to avoid this situation in the future."