I was thinking it might be better to simply track if cdb2_run_statment has ever received a ping-pong request, and if so skip donating to sockpool (and so no need to drain connection). Don't want to disable it by default.

Also need to patch consume_previous_query in the API.

bb-cdb2api does not have auto-consume in cdb2_close, but does in cdb2_run_statement:

   else if (hndl->ack) {
       hndl->ack = 0;
       if (hndl->sb) {
           int fd = cdb2buf_fileno(hndl->sb);
           shutdown(fd, SHUT_RDWR);
       }
   }
   else {
       while(cdb2_next_record_int(hndl) == CDB2_OK);
   }

This is insufficient, as user might have called cdb2_clear_ack. I think we need to track if prior cdb2_run_statement was for a consumer or not (here and bb-cdb2api as well).

Yes you're right. We need to patch these places for a mixed use of 'exec procedure' on a consumer and regular queries.

Let us disable for now - we can make it robust later.