How Facebook Syncs Time Across Millions of Servers

Facebook faced significant challenges in maintaining precise time synchronization across millions of servers due to inaccuracies in internal clock oscillators. Initially, they used Network Time Protocol (NTP) and later switched to Precision Time Protocol (PTP) to achieve nanosecond-level precision. The transition was driven by the need for higher accuracy to support advanced systems and applications like the metaverse. PTP uses hardware timestamping and transparent clocks to mitigate latency and improve synchronization. This implementation enhances various operations, including logging, coordination, and handling user requests in a distributed system.