On 2021/02/11 21:55, Michael Paquier wrote:
> Hi Fujii-san,
>
> On Tue, Feb 09, 2021 at 11:17:04PM +0900, Fujii Masao wrote:
>> ISTM that the commit 2c8dd05d6c caused this issue. The commit changed
>> pg_stat_get_wal_receiver() so that it reads "writtenUpto" by using
>> pg_atomic_read_u64(). But since "writtenUpto" is initialized only when
>> walreceiver starts up, reading "writtenUpto" before the startup of
>> walreceiver can cause the error.
>
> Indeed, that's a problem. We should at least move that out of the
> spin lock area.
Yes, so what about the attached patch?
We didn't notice this issue long time because no regression test checks
pg_stat_wal_receiver. So I included such test in the patch.
Regards,
--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION