Re: Issue with the PRNG used by Postgres

On Wed, Apr 10, 2024 at 12:40 PM Parag Paul <parag.paul@gmail.com> wrote:
> The reason why this could be a problem is a flaw in the RNG with the enlarged Hamming belt.
> I attached an image here, with the RNG outputs from 2 backends. I ran our code for weeks, and collected ther
> values generated by the RNG over many backends. The one in Green (say backend id 600), stopped flapping values and
> only produced low (near 0 ) values for half an hour, whereas the Blue(say backend 700), kept generating good values
andhad 
> a range between [0-1)
> During this period, the backed 600 suffered and ended up with spinlock stuck condition.

This is a very vague description of a test procedure. If you provide a
reproducible series of steps that causes a stuck spinlock, I imagine
everyone will be on board with doing something about it. But this
graph is not going to convince anyone of anything.

--
Robert Haas
EDB: http://www.enterprisedb.com