Re: dsa_allocate() faliure

Hi Thomas,
it is a Production system and we don’t have permanent access to it.
Also to have an auto_explain feature always on, is not an option in production.
I will ask the customer to give us notice asap the error present itself to connect immediately and try to get a query plan.

Regards

Fabio Isabettini
www.voipfuture.com

> On 30. Jan 2019, at 04:13:14, Thomas Munro <thomas(dot)munro(at)enterprisedb(dot)com> wrote:
>
> On Tue, Jan 29, 2019 at 10:32 PM Fabio Isabettini
> <fisabettini(at)voipfuture(dot)com> wrote:
>> we are facing a similar issue on a Production system using a Postgresql 10.6:
>>
>> org.postgresql.util.PSQLException: ERROR: EXCEPTION on getstatistics ; ID: EXCEPTION on getstatistics_media ; ID: uidatareader.
>> run_query_media(2): [a1] REMOTE FATAL: dsa_allocate could not find 7 free pages
>
>> We would like not to stop the Production system and upgrade it to PG11. And even though would this guarantee a permanent fix?
>> Any suggestion?
>
> Hi Fabio,
>
> Thanks for your report. Could you please also show the query plan
> that runs on the "remote" node (where the error occurred)?
>
> There is no indication that upgrading to PG11 would help here. It
> seems we have an undiagnosed bug (in 10 and 11), and so far no one has
> been able to reproduce it at will. I personally have chewed a lot of
> CPU time on several machines trying various plan shapes and not seen
> this or the possibly related symptom from bug #15585 even once. But
> we have about three reports of each of the two symptoms. One reporter
> wrote to me off-list to say that they'd seen #15585 twice, the second
> time by running the same query in a tight loop for 8 hours, and then
> not seen it again in the past 3 weeks. Clearly there is issue needing
> a fix here, but I don't yet know what it is.
>
> --
> Thomas Munro
> http://www.enterprisedb.com
>