· Chuck Conway · Software Development · 1 min read
Understanding Time Discrepancies in Distributed Systems
While UTC provides a common time standard, assuming perfect synchronization between servers using UTC can lead to data inconsistencies and unexpected errors.
A friend pointed out that all UTC Time is not the same. When he told me, I responded with “What!?! What are you talking about? It’s the same.” “No it’s not” he said. He explained, that yes using UTC will allot you an agreed upon time format but that does not guarantee that both server’s clocks are synchronized.
For example, Sever A calls server B for updates. Both Servers use UTC Time. Server A sends over a timestamp, how do we know that the two servers clocks are synchronized and that the two times match, we don’t. The odds are they are not. How can they be? Absolute time does not exist. It’s all relative. By using a timestamp to retrieve data from another server you are making an assumption that both servers have the same time.
