Re: [16+] subscription can end up in inconsistent state

On Mon, Sep 11, 2023 at 3:00 PM Jeff Davis <pgsql@j-davis.com> wrote:
> On Mon, 2023-09-11 at 08:59 +0530, Amit Kapila wrote:
> > Can we think of calling walrcv_check_conninfo() when the following
> > check is true (MySubscription->passwordrequired &&
> > !superuser_arg(MySubscription->owner))? IIUC this has to be done for
> > both apply_worker and tablesync_worker.
>
> To me, it would make sense to just have walrcv_connect() do both checks
> (a) and (b) -- rather than only check (b) -- when must_use_password is
> true. Separating these checks (which are really two parts of the same
> check) led to this problem in the first place.

Sorry for the slow response. I agree with this, and I also think that
keeping the existing checks makes sense.

> Another thought: we may also need to invalidate the subscription worker
> in cases where a user loses their superuser status.

I am not sure whether there's any problem here. I don't think it's
important that the worker realizes that it's lost superuser
instantaneously. But it should probably realize it, say, at the next
transaction boundary.

--
Robert Haas
EDB: http://www.enterprisedb.com