Randomizing Strings In A Microservices World

[Tim Daneliuk]

On 12/9/19 8:54 PM, Dennis Lee Bieber wrote:
> On Mon, 9 Dec 2019 18:52:11 -0600, Tim Daneliuk <info at tundraware.com>
> declaimed the following:
> 
>>
>> - Each of these services needs to produce a string of ten digits guaranteed to be unique
>>  on a per service instance basis AND to not collide for - oh, let's say - forever :)s
>>
>> Can anyone suggest a randomization method that might achieve this efficiently?
>>
>> My first thought was to something like nanonseconds since the epoch plus something
>> unique about the service instance - like it's IP?  (This is in a K8s cluster) - to
>> see the randomization and essentially eliminate the string being repeated.
>>
>> Ideas welcome ..
>>
> 
> 	Well, 10 digits is rather short, but studying
> https://en.wikipedia.org/wiki/Universally_unique_identifier might provide
> some ideas.
> 
> 

For a variety of reasons the length of this string cannot exceed 10 digits.  It is believed
that - in this application - the consumption of values will be sparse over time.  All
I really need is a high entropy way to select from among the billion possible values to
minimize the possibility of collisions (which require retry and time we don't want to burn).