tldr

Date: 2025-12-23 Source: https://arpitbhayani.me/blogs/clock-sync-nightmare

But we engineers lose sleep over something as basic as keeping clocks in sync.

But we engineers lose sleep over something as basic as keeping clocks in sync.
The Illusion of Accurate Time: Every computer has an internal clock, typically driven by a quartz crystal oscillator.
Why Clock Skew Breaks Things: Clock skew = the difference in time between two clocks at any given instant.
Physical Clock Synchronization: The simplest approach to clock synchronization is to periodically query a trusted time server and adjust local clocks accordingly.
Milliseconds Are Not Enough: For many applications, NTP accuracy is sufficient.
Logical clocks and causality: Lamport introduced the concept of logical clocks based on a simple observation: if two events are causally related, we should be able to order them.

Date: 2025-12-23 Source: https://arpitbhayani.me/blogs/clock-sync-nightmare

But we engineers lose sleep over something as basic as keeping clocks in sync.

But we engineers lose sleep over something as basic as keeping clocks in sync.
The Illusion of Accurate Time: Every computer has an internal clock, typically driven by a quartz crystal oscillator.
Why Clock Skew Breaks Things: Clock skew = the difference in time between two clocks at any given instant.
Physical Clock Synchronization: The simplest approach to clock synchronization is to periodically query a trusted time server and adjust local clocks accordingly.
Milliseconds Are Not Enough: For many applications, NTP accuracy is sufficient.
Logical clocks and causality: Lamport introduced the concept of logical clocks based on a simple observation: if two events are causally related, we should be able to order them.