Subj : Re: anyway the wind blows
To   : Maurice Kinal
From : Wilfred van Velzen
Date : Wed Apr 14 2021 10:43:48

Hi Maurice,

On 2021-04-13 21:15:41, you wrote to August Abolins:

 AA>> Is that a way to reduce the probability of collisions within a
 AA>> certain span of allotted time?

 MK> Good question.  I've heard of a few different methods for doing this none
 MK> of which I am currently deploying.  Mind you I take care of MSGIDs in the
 MK> creation of the MSG so the possiblity of collisions is near zero.  There is
 MK> a way but if that happens then it is a signal that something is seriously
 MK> wrong on my system.  It has yet to happen.

 MK> Just for fun here is the output of 10 potential MSGID serailno's, the first
 MK> column being unixtime 32-bit hex based, the second being the random 8
 MK> character [:alnum:] regex dealies;

 MK> 60760e0b kUBdI5RO
 MK> 60760e0b G5T1LBae
 MK> 60760e0b mFSS1Gxc
 MK> 60760e0b Daxpq9EE
 MK> 60760e0b XVCgstYj
 MK> 60760e0b uWuB7Jqj
 MK> 60760e0b J0qZbQIo
 MK> 60760e0b kGrnLcEZ
 MK> 60760e0b NQGnXOVM
 MK> 60760e0b kK7htVJO

 MK> Note that only one method produced zero collisions while the other produced
 MK> nothing but collisions.  Based on this very simple test the random 8
 MK> character [:alnum:] regex thingies are obviously superior.

So your algorithm based on unixtime has a bug! It should take into account it can be called multiple times within the same second. If you do that correctly, it's superior to the random one...

Bye, Wilfred.

--- FMail-lnx64 2.1.0.18-B20170815
 * Origin: FMail development HQ (2:280/464)

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