Re: tx canceled on standby despite infinite max_standby_streaming_delay

On Sat, May 14, 2016 at 12:27 PM, Jay Howard <jhoward(at)alumni(dot)utexas(dot)net>
wrote:

> I'm seeing long-running transactions (pg_dump) canceled on the standby
> when there are a lot of inserts happening on the master. This despite my
> having set max_standby_streaming_delay to -1 on the standby.
>

Do you have hot_standby_feedback set to "on" ?

What is the parameter max_standby_archive_delay configured to ? This will
pause WAL archives from being applied when queries are executed on the
standby database.

> Why might that happen?
>
> This is pg 9.3.12. When it happens I see:
>
> pg_dump: Dumping the contents of table "TABLE" failed: PQgetResult()
> failed.
> pg_dump: Error message from server: ERROR: canceling statement due to
> conflict with recovery
> DETAIL: User query might have needed to see row versions that must be
> removed.
> pg_dump: The command was: COPY public.TABLE (COLUMNS) TO stdout;
>

I suspect this is due to the clean up by VACUUM on primary.

Regards,
Venkata B N

Fujitsu Australia