On Mon, Apr 08, 2024 at 05:42:05PM +0000, Leung, Anthony wrote: > Are you suggesting that we check if the backend is B_AUTOVAC in > pg_cancel/ terminate_backend? That seems a bit unclean to me since > pg_cancel_backend & pg_cancel_backend does not access to the > procNumber to check the type of the backend. > > IMHO, we can keep SIGNAL_BACKEND_NOAUTOVACUUM but just improve the > errmsg / errdetail to not expose that the backend is an AV > worker. It'll also be helpful if you can suggest what errdetail we > should use here.
The thing is that you cannot rely on a lookup of the backend type for the error information, or you open yourself to letting the caller of pg_cancel_backend or pg_terminate_backend know if a backend is controlled by a superuser or if a backend is an autovacuum worker.
Good catch. Thanks. I think we need to update the error message to not leak backend type info.
> The choice of pg_signal_autovacuum is a bit inconsistent, as well, > because autovacuum workers operate like regular backends. This name > can also be confused with the autovacuum launcher.
Ok. What would be a good choice? Is `pg_signal_autovacuum_worker` good enough?
