* Twitter blames bug in infrastructure
* Hackers claim involvement in disruption
* Users complain of lack of platform to complain
(Edits lead, adds comments from Twitter)
By Gerry Shih and Joseph Menn
SAN FRANCISCO, June 21 A double outage rocked
Twitter on Thursday, as users worldwide reported significant
down-time and slow service across the website and mobile
applications of the microblogging platform.
The outages left another bruise on a service that earned a
reputation for unreliability in its early days.
The San Francisco-based company blamed the disruption on a
"cascading bug" in one of its infrastructure components.
"One of the characteristics of such a bug is that it can
have a significant impact on all users, worldwide, which was the
case today," Mazen Rawashdeh, a Twitter vice president of
engineering, wrote in a blog post after normal service resumed.
"This wasn't due to a hack or our new office or Euro 2012 or
GIF avatars, as some have speculated today."
"We are currently conducting a comprehensive review to
ensure that we can avoid this chain of events in the future," he
Twitter's statements came amid speculation that hackers
contributed to the disruption.
UgNazi - an emerging hacker outfit that recently gained
publicity for breaking into Cloudflare chief executive Matthew
Prince's personal Google email account - claimed credit for the
service disruption in an email to Reuters, saying it launched a
distributed denial-of-service (DDoS) attack against Twitter
because of the company's support for the Cyber Intelligence
Sharing and Protection Act.
One security professional said the group probably used a
DDoS-for-hire site to launch an attack against Twitter on
Thursday, but played down the likelihood the group was
responsible for bringing down the social media network.
"It was mere coincidence," the security professional said.
"The backend of Twitter is having issues, which is unrelated to
the very small attack."
North American traffic levels for Twitter.com plummeted on
two occasions between 8.30 a.m. PDT (1530 GMT) and 11.00 a.m.
PDT (1800 GMT), according to data provided by network analytics
The first outage lasted between 8.30 a.m. (1530 GMT) and
10.00 a.m. (1700 GMT), data showed.
Twitter acknowledged the disruption in a mid-morning blog
post that was continually revised as the service resumed, only
to fail for a second time before 11.00 a.m.
As the service resumed on Thursday, its most dedicated users
quickly hopped back on to crack jokes, express relief and
complain that during the outage they had nowhere to complain
about the interruption.
Founded in 2006, Twitter was plagued in its early days by
frequent outages as it struggled to handle the ever-rising
volume of tweets, leaving frustrated users with its famous "fail
whale" error screen.
In recent years, Twitter, under pressure to demonstrate
financial viability, has devoted considerable resources toward
improving reliability in a move to project itself as a mature,
CEO Dick Costolo said this month that Twitter now has 140
million active monthly users who send 400 million tweets daily.
The company conceded on Thursday it had failed users who
rely on it to connect with "heroes, causes, political
"It's imperative that we remain available around the world,"
said Rawashdeh, "and today we stumbled."
(Reporting By Gerry Shih, Joseph Menn and Mauro Whiteman;
Editing by Edwin Chan and David Cowell)