On Mon, Aug 3, 2015 at 1:30 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> I haven't looked to find out why the unlinks happen in this order, but on
> a heavily loaded machine, it's certainly possible that the process would
> lose the CPU after unlink("postmaster.pid"), and then a new postmaster
> could get far enough to see the socket lock file still there. So that
> would account for low-probability failures in the pg_upgradecheck test,
> which is exactly what we've been seeing.
Oh... This may explain the different failures seen with TAP tests on
hamster, and axolotl with pg_upgrade as well. It is rather easy to get
them heavily loaded.
--
Michael
