Thread: spurious /dev/shm related errors on insert

Michael Charnoky <noky@noky.net> writes:
> Hi, I'm seeing random errors from an application that is performing DB
> inserts. The error happens spuriously and looks like this from the
> application side:

> could not open file "/dev/shm/postgres_apptable_47861701461760" for
> reading: No such file or directory

Offhand I do not believe that any part of the core PG code would attempt
to access such a file.  Maybe you've got some extensions in there that
would do so?

            regards, tom lane

On Fri, 2016-03-18 at 10:45 -0400, Michael Charnoky wrote:
> I should have noted: the application is using PostgreSQL 9.5.0,
> running on Ubuntu 14.04
>
> Mike
>
> On Fri, Mar 18, 2016 at 10:41 AM, Michael Charnoky <noky@noky.net>
> wrote:
> > Hi, I'm seeing random errors from an application that is performing
> > DB inserts. The error happens spuriously and looks like this from
> > the application side:
> >
> > could not open file "/dev/shm/postgres_apptable_47861701461760" for
> > reading: No such file or directory
> >
> > The PostgreSQL logs show:
> >
> > 2016-03-18 07:25:01 UTC ERROR:  could not open file
> > "/dev/shm/postgres_apptable_47861701461760" for reading: No such
> > file or directory
> > 2016-03-18 07:25:01 UTC STATEMENT:  COPY urltable FROM
> > '/dev/shm/postgres_apptable_47861701461760' USING DELIMITERS '#'
> > WITH NULL AS '\null';
> >
> > Any clues? I couldn't find any similar issues reported by other
> > users. Thanks!
> >
> > Mike
> >
> >


Running 9.5.1 installed from Debian packages, when Postgres is started
it creates this file in /dev/shm


-rw------- 1 postgres postgres 2316 Mar 19 05:24 PostgreSQL.1804289383

It's binary.

Bye.

On Mar 18, 2016 10:59 AM, "Tom Lane" <tgl@sss.pgh.pa.us> wrote:
> Offhand I do not believe that any part of the core PG code would attempt
> to access such a file.  Maybe you've got some extensions in there that
> would do so?

Thanks Tom, thought this was a PG issue. I'll dig more into the guts of the application