Universally Unique Identifer (Uuid)

UUID is a 128-bit number of an unique id. It has very low chance of getting collision.

According to Wikipedia, generating 1 billion UUIDs every second for 100 years the probability of creating a single duplicate reach 50%.

Example of UUID:

09c93e62-50b4-468d-bf8a-c07e1040bfb2

We can use this independently in each server:

Pros:

• Simple, no dependency, dont need to synchronise
• Easy to scale because ID gen is in the webserver itself

Cons:

• 128 bit long, might be too much for some system
• ID does not scale with time
• ID can be non-numeric