As the clock turned 12 at the end of June 30, the International Earth Rotation and Reference Systems Service added a second more to Earth’s time to keep atomic clocks synchronized with the changing rotation speed of the planet.
Unfortunately for websites running on systems that rely on the Network Time Protocol (NTP), adding a second more to the clock caused outages in some parts of the Web because their systems weren’t aware how to handle the added second.
One of those who acknowledged the “leap second” bug was popular news-sharing site Reddit, which said: “We are having some Java/Cassandra issues related to the leap second at 5pm PST. We’re working as quickly as we can to restore service.”
According to technology magazine Wired.com, many of those affected were running on systems powered by the Java application platform as well as the Linux operating system. It ventured that services such as Foursquare, Yelp, LinkedIn, Gawker, and StumbleUpon were among those affected.
This is on top of the online services that went down due to an Amazon Web Services outage caused by power problems in one of its US datacenters.
“Many computing systems use what’s called the Network Time Protocol, or NTP, to keep themselves in sync with the world’s atomic clocks, and when an extra second is added, some just don’t know how to handle it,” the Wired report explained.
One of those who came out unscathed from the leap second outage was Google, who devised a technique called a “leap smear” to avoid accidental downtimes due to the phenomenon.
“We modified our internal NTP servers to gradually add a couple of milliseconds to every update, varying over a time window before the moment when the leap second actually happens,” Google said in an earlier blog post.
“This meant that when it became time to add an extra second at midnight, our clocks had already taken this into account, by skewing the time over the course of the day,” it added.
The next leap second is expected to be added around 2015 or 2016, scientists say. There have been a total of 25 leap seconds added to the world’s time since it was introduced in 1972, the last one occurring on January of 2009.
Websites suffer hiccups after addition of ‘leap second’
1 reply to this topic
Posted 02 July 2012 - 10:57 AM