Hello, Peter.
Pgpool used only from App side at another server.
Zabbix running its queries directly at database server.
16.04.2018, 21:03, "Peter Geoghegan" <pg@bowt.ie>:
> On Mon, Apr 16, 2018 at 10:48 AM, Alvaro Herrera
> <alvherre@alvh.no-ip.org> wrote:
>> and tuplestore_end does this:
>> if (state->myfile)
>> BufFileClose(state->myfile);
>> without setting anything in state to NULL; so we're relying on the
>> caller fs->tstore to null to avoid repeated tuplestore_end calls. I
>> can't see any way for this to misbehave, but maybe the funcstate appears
>> more than once in the PerFuncState array, and we clean it correctly the
>> first time around and then invoke the tuplestore_end() the second time
>> to the memory that was previously freed? I think this makes no sense
>> unless we share FunctionScanPerFuncState elements -- do we?
>
> I have no reason to think that we do. Offhand, I find it more likely
> that some executor slot that imagines that it owns the tuple frees the
> tuple once, which is followed by a call to tuplestore_end() that frees
> the same tuple a second time (a double-free). As I mentioned, we've
> seen several bugs of that general variety in both tuplestore and
> tuplesort in the past. Some of these have been very subtle.
>
> Note that pgpool is involved here. I don't know much about pgpool, and
> maybe that's totally irrelevant.
>
> --
> Peter Geoghegan