On Sat, Nov 25, 2017 at 05:45:59PM -0500, Tom Lane wrote:
> Justin Pryzby <pryzby@telsasoft.com> writes:
> > We never had any issue during the ~2 years running PG96 on this VM, until
> > upgrading Monday to PG10.1, and we've now hit it 5+ times.
>
> > BTW this is a VM run on a hypervisor managed by our customer:
> > DMI: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 06/22/2012
>
> > Linux TS-DB 2.6.32-431.el6.x86_64 #1 SMP Fri Nov 22 03:15:09 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
>
> Actually ... I was focusing on the wrong part of that. It's not
> your hypervisor, it's your kernel. Running four-year-old kernels
> is seldom a great idea, and in this case, the one you're using
> contains the well-reported missed-futex-wakeups bug:
>
> https://bugs.centos.org/view.php?id=8371
>
> While rebuilding PG so it doesn't use POSIX semaphores will dodge
> that bug, I think a kernel update would be a far better idea.
> There are lots of other known bugs in that version.
>
> Relevant to our discussion, the fix involves inserting a memory
> barrier into the kernel's futex call handling:
Ouch ! Thanks for the heads up and sorry for the noise.
I'm still trying to coax 3 customers off centos5.x, so the 2 customers left
running centos6.5 weren't on any of my mental lists..
Justin