[ENW-P-C-2016200] about leap second impact on Agile Controller-campus product warning

Early warning number: ENW-P-C-2016200

Product family

DCN&Campus Controller PDU

Product model

Agile Controller-Campus

Release Date

2016 -12 -27



Versions Involved

All Agile Controller-campus versions running in the Linux system

Equipment involved.


Application scope



Early warning

Operation requirements


Completion time:

Before the 2016 -12 -31

Labor hour

0.5 man/day

Contact information

The contact of the product.

Zhang Yu   00281427

Service contact person

Han Ruobing 00230830

Release scope

Customer (C)

Keyword: Linux, leap second


1.       Leap second jump may lead to Linux operating system is suspended.

2.       Services are interrupted.

[ Problem Description ]

International standard time UTC (Coordinated Universal Time, coordinated universal time) will be implemented in January 1, 2017 a positive leap second, namely, add 1 s. Beijing time of January 1, 2017 fifty nine minutes fifty nine seconds when 7 and global synchronization adjust the leap second, when the time comes it will appear 7:59: 60 special phenomenon.

[ Version  Involved ]

1.       RedHat Enterprise Linux before 6.4 versions, and the kernel version is before kernel-2.6.32-131.30.2, kernel-2.6.32-220.25.1.el6 and kernel-2.6.32-279.5.2 are involved.

2 SuSE Enterprise Linux 12 and the versions before, this problem is involved.


[ Reason/trigger conditions ]

UTC time (GMT +0) December 31, 2016 23:59: 59 (corresponding to the beijing (GMT+8) time January 1, 2017 7:59: 59, calculated based on the local time zone elsewhere in local time),   leap second at the time of adjustment, if the NTP service is enabled, and trigger the clock synchronization, which causes the system kernel BUG, will cause the host system breakdown.

[Measures and Solutions ]

Aiming at the SuSE Linux scenario example:

In 2016 -12 -30 discontinued the NTP service to stop synchronizing time from the external NTP clock source.

execute rcntp stop in terminal (RedHat corresponding command is service ntpd stop)

Agile-1:~# rcntp stop

Shutting down network time protocol daemon (NTPD)

On 2017 -01 -01 recovery the service

execute rcntp start in terminal (RedHat corresponding command is service ntpd restart)

Agile-1:~# rcntp start

Starting network time protocol daemon (NTPD)