Posted On: Nov 2, 2021

Amazon Time Sync Service now allows you to easily generate and compare timestamps from Amazon EC2 instances with ClockBound, an open source daemon and library. This information is valuable to determine order and consistency for events and transactions across EC2 instances, independent from the instances’ respective geographic locations. ClockBound calculates your Amazon EC2 instance’s clock error bound to measure its clock accuracy and allows you to check if a given timestamp is in the past or future with respect to your instance’s current clock. On every call, ClockBound simultaneously returns two pieces of information: the current time and the associated absolute error range. This means that the actual time of a ClockBound timestamp is within a set range.

To get started, first make sure you are using Chrony. Then install the ClockBound daemon and library, or build your own library to integrate ClockBound into your application. For the best clock accuracy, we also recommend using the Amazon Time Sync Service. The Amazon Time Sync Service and Chrony are configured by default on Amazon Linux 2 instances.

To learn more about ClockBound, including installation instructions, see ClockBound on GitHub.

To learn more about the Amazon Time Sync Service, see setting your time in the EC2 user guide.

To read more about clock accuracy and clock error bound, refer to this blog post.