This blog discusses how to prepare your database for the new leap second coming in the new year.

At the end of this year, on December 31, 2016, a new leap second gets added. Many of us remember the huge problems this caused back in 2012. Some of our customers asked how they should prepare for this year’s event to avoid any unexpected problems.

It’s a little late, but I thought discussing the issue might still be useful.

The first thing is to make sure your systems avoid the issue with abnormally high CPU usage. This was an problem in 2012 due to a Linux kernel bug. After the leap second was added, CPU utilization sky-rocketed on many systems, taking down …

Sheeri K. Cabral at the Mozilla Foundation wrote about an issue with the June 30th 2012 leap second affecting at least MySQL, Java and Minecraft servers. It now appears that the underlying cause is a Linux kernel bug, as noted by John Stultz (IBM) on the Linux Kernel mailing list, and the team Sheeri is part of deserves due credit for doing awesome pattern recognition and being the first to bring it to public attention, enabling people to quickly correlate their own experience with that of others and finding a practical solution as well as helping figure out the cause.

Sheeri’s original post MySQL and the Leap Second, High CPU and the Fix describes how MySQL servers would suddenly exhibit high CPU usage during a period of low load. …