Re: OOM in libpq and infinite loop with getCopyStart()

On Mon, Mar 21, 2016 at 10:13 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>
> On Tue, Mar 1, 2016 at 12:38 AM, Michael Paquier
> <michael(dot)paquier(at)gmail(dot)com> wrote:
> > Thoughts? I have registered that in the CF app, and a patch is attached.
>
> It is very difficult to believe that this is a good idea:
>
> --- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
> +++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
> @@ -445,6 +445,7 @@ libpqrcv_PQexec(const char *query)
> if (PQresultStatus(lastResult) == PGRES_COPY_IN ||
> PQresultStatus(lastResult) == PGRES_COPY_OUT ||
> PQresultStatus(lastResult) == PGRES_COPY_BOTH ||
> + PQresultStatus(lastResult) == PGRES_FATAL_ERROR ||
> PQstatus(streamConn) == CONNECTION_BAD)
> break;
> }
>
> I mean, why would it be a good idea to blindly skip over fatal errors?
>

I think it is not about skipping the FATAL error, rather to stop trying to
get further results on FATAL error. This is to ensure that OOM error is
reported rather that ignored. There has been discussion about this
previously as well [1].

[1] -
http://www.postgresql.org/message-id/CAB7nPqT6gKj6iS9VTPth_h6Sz5Jo-177s6QJN_jrW66wyCjJ=w@mail.gmail.com

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com