Will Leap Second crash DB2?

19 June,2015 by Jack Vamvas

Question: What is a leap second and how will it impact my DB2 servers ? I have a bunch of DB2 servers hosted on Red Hat Linux 6.

Answer: It’s important to understand the definition of  a leap second . I’m quoting from Wikipedia

“A leap second is a one-second adjustment that is occasionally applied to Coordinated Universal Time (UTC) in order to keep its time of day close to the mean solar time, or UT1. Without such a correction, time reckoned by Earth's rotation drifts away from atomic time because of irregularities in the Earth's rate of rotation. Since this system of correction was implemented in 1972, 25 such leap seconds have been inserted. The most recent one happened on June 30, 2012 at 23:59:60 UTC.[1] A leap second, the 26th, will again be inserted at the end of June 30, 2015 at 23:59:60 UTC.[2]”

According to IBM - Leap seconds are fully supported by DB2 on systems which use the UTC timescale.

DB2 utilises the Linux  OS timsecales. The Linux OS timescales by default are typically based on UTC. Although you should double check the OS is not utilising  TAI (International Atomic Time). TAI which is not supported by DB2.

On 30 June, 2012 there was a leap second. There were some reported cases of high Linux CPU on certain products .

Some Useful Links about Leap Second and the impact on other software

A documented example related to WebSphere MQ queue manager.

Understanding the impact of the leap second


Read More on Measuring Linux CPU and OS

Display Linux CPU information - DBA DB2

Database tuning and Operating System Tuning - DBA DB2



Author: Jack Vamvas(http://www.dba-db2.com)


Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Your comment could not be posted. Error type:
Your comment has been saved. Comments are moderated and will not appear until approved by the author. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.


Post a comment on Will Leap Second crash DB2?

Comments are moderated, and will not appear until the author has approved them.

dba-db2.com | DB2 Performance Tuning | DBA DB2:Everything | FAQ | Contact | Copyright