Understanding Leap Second Impact and NTP Synchronization in Identity Manager

Products

• CA Identity Manager
• CA Identity Governance
• CA Identity Portal
• CA Identity Suite

Issue/Introduction

This article explains how Identity Manager interacts with operating system time and potential impacts regarding leap second events. It provides guidance on time synchronization using Network Time Protocol (NTP) to ensure system reliability.

Environment

Identity Manager

Resolution

 Identity Manager relies on the operating system time for internal processing.

• NTP Synchronization: Most server environments utilize NTP to maintain accurate time. NTP protocols are designed to handle leap seconds automatically by including a leap second flag in the network protocol headers.
• Proactive Notification: When the leap second flag is set, the system receives a notification, often with up to one month of lead time, ensuring the client is aware of the impending adjustment.
• Operating System Standards: According to the standard tm_sec member definitions within the tm structure, seconds are represented in the range of [0, 60] inclusive. This standard range allows for the leap second (60) event without causing errors in most applications.

Technical Context

• NTP Protocol v4 (RFC 5905): Systems compliant with RFC 5905 receive leap second notifications via NTP headers. Synchronization does not need to occur at the exact moment (23:59:60) the leap second is added; the protocol handles the adjustment throughout the month.
• Impact: The risk of a synchronization conflict during the exact leap second is statistically small. Ensure your NTP configuration is properly maintained to receive standard protocol updates.

Reference For detailed technical specifications regarding NTP, refer to RFC 5905.