Re: Out of Memory errors are frustrating as heck!

On Mon, Apr 15, 2019 at 12:34 PM Gunther <raj(at)gusw(dot)net> wrote:

> Breakpoint 2, AllocSetAlloc (context=0x1168230, size=8272) at aset.c:715
> 715 {
> (gdb) p context->name
> $8 = 0x96ce5b "ExecutorState"
>
>
I think that the above one might have been the one you wanted.

> I guess I should run this for a little longer. So I disable my breakpoints
>
>
it went up pretty quick from 1.2 GB to 1.5 GB, but then it stopped growing
> fast, so now back to gdb and break:
>
Unfortunately, I think this means you missed your opportunity and are now
getting backtraces of the innocent bystanders.

Particularly since you report that the version using nested loops rather
than hash joins also leaked, so it is probably not the hash-join specific
code that is doing it.

What I've done before is compile with the comments removed from
src/backend/utils/mmgr/aset.c:/* #define HAVE_ALLOCINFO */

and then look for allocations sizes which are getting allocated but not
freed, and then you can go back to gdb to look for allocations of those
specific sizes. This generates a massive amount of output, and it bypasses
the logging configuration and goes directly to stderr--so it might not end
up where you expect.

Thanks for the view definition. Nothing in it stood out to me as risky.

Cheers,

Jeff