Re: BUG #18428: Connection broken but DB service still alive.

PG Bug reporting form <noreply@postgresql.org> writes:
> 2024-04-06 13:54:53.868 CST [4840] LOG:  received fast shutdown request

Something is sending your postmaster a shutdown signal (SIGINT).
You need to figure out how that is happening.

In the Windows world I think the most likely theory is that some
script is mistakenly issuing "pg_ctl stop"; the signal mechanism
we use on that platform doesn't map onto anything else people would
commonly do.  But that's a guess.  There's no hard evidence about
the signal source here.

            regards, tom lane