Re: Pre-allocation of shared memory ...

Tom Lane wrote:
> Hans-Jürgen Schönig <hs@cybertec.at> writes:
> > I have two explanations for the following behaviour:
> > a. a bug
> > b. not enough shared memory
> 
> > WARNING:  Message from PostgreSQL backend:
> >     The Postmaster has informed me that some other backend
> >     died abnormally and possibly corrupted shared memory.
> 
> Is this a Linux machine?  If so, the true explanation is probably (c):
> the kernel is kill 9'ing randomly-chosen database processes whenever
> it starts to feel low on memory.  I would suggest checking the
> postmaster log to determine the signal number the failed backends are
> dying with.  The client-side message does not give nearly enough info
> to debug such problems.
> 
> There is also possibility (d): you have some bad RAM that is located in
> an address range that doesn't get used until the machine is under full
> load.  But if the backends are dying with signal 9 then I'll take the
> kernel-kill theory.
> 
> AFAIK the only good way around this problem is to use another OS with a
> more rational design for handling low-memory situations.  No other Unix
> does anything remotely as brain-dead as what Linux does.  Or bug your
> favorite Linux kernel hacker to fix the kernel.

Is there no sysctl way to disable such kills?

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