Re: Out of Memory errors are frustrating as heck!

On Tue, Oct 8, 2019 at 12:44 PM Merlin Moncure <mmoncure(at)gmail(dot)com> wrote:
> On Sun, Apr 14, 2019 at 3:51 PM Gunther <raj(at)gusw(dot)net> wrote:
> >
> > For weeks now, I am banging my head at an "out of memory" situation. There is only one query I am running on an 8 GB system, whatever I try, I get knocked out on this out of memory. It is extremely impenetrable to understand and fix this error. I guess I could add a swap file, and then I would have to take the penalty of swapping. But how can I actually address an out of memory condition if the system doesn't tell me where it is happening?
> > We can't really see anything too worrisome. There is always lots of memory used by cache, which could have been mobilized. The only possible explanation I can think of is that in that moment of the crash the memory utilization suddenly skyrocketed in less than a second, so that the 2 second vmstat interval wouldn't show it??? Nah.
> >
> > I have already much reduced work_mem, which has helped in some other cases before. Now I am going to reduce the shared_buffers now, but that seems counter-intuitive because we are sitting on all that cache memory unused!
> >
> > Might this be a bug? It feels like a bug. It feels like those out of memory issues should be handled more gracefully (garbage collection attempt?) and that somehow there should be more information so the person can do anything about it.
>
> I kind of agree that nothing according to vmstat suggests you have a
> problem. One thing you left out is the precise mechanics of the
> failure; is the database getting nuked by the oom killer? Do you have
> the logs?

oops, I missed quite a bit of context upthread. sorry for repeat noise.

merlin