Effect of 1/1/2017 leap second on ECS and our solution

Dear Alibaba Cloud Users,

The International Earth Rotation and Reference Systems Service's (IERS) Earth Orientation Centre recently used Twitter to confirm that a leap second will be added to coordinated universal time (UTC) after 12/31/2016 23:59:59 GMT (1/1/2017 07:59:59 Beijing time). After this additional second, the new year will begin. Due to the time difference, China will add this extra second after 7:59:59 Beijing time on 1/1/2017 to keep in sync with global time. This will result in a special occurrence, the time 7:59:60.

1. If the applications and business you operate on ECS are not very dependent on the system time, this leap second will not affect you.

2. However, if your applications and business require exact system time precision and the NTP on your ECS instances uses the Alibaba Cloud default NTP service, this leap second may affect your applications or businesses. In this case, please carefully read the Alibaba Cloud NTP service adjustment plan, evaluate potential risks, and take measures to avoid them.

The Alibaba Cloud NTP service for ECS instances will ignore the leap second and gradually synchronize with international time to eliminate the 1 second time difference the leap second will cause. The details of the Alibaba Cloud NTP service clock refers to:https://intl.aliyun.com/help/faq-detail/48436.htm

Best regards

The Alibaba Cloud Team

Dec.19, 2016