Re: [HACKERS] logical decoding of two-phase transactions

On Fri, Jun 18, 2021 at 7:43 AM Peter Smith <smithpb2250(at)gmail(dot)com> wrote:
>
> On Thu, Jun 17, 2021 at 6:22 PM Greg Nancarrow <gregn4422(at)gmail(dot)com> wrote:
> >
> > For example, in the v86-0001 patch:
> >
> > +/*
> > + * Handle PREPARE message.
> > + */
> > +static void
> > +apply_handle_prepare(StringInfo s)
> > +{
> > + LogicalRepPreparedTxnData prepare_data;
> > + char gid[GIDSIZE];
> > +
> > + logicalrep_read_prepare(s, &prepare_data);
> > +
> > + Assert(prepare_data.prepare_lsn == remote_final_lsn);
> >
> > The above Assert() should be changed to something like:
> >
> > + if (prepare_data.prepare_lsn != remote_final_lsn)
> > + ereport(ERROR,
> > + (errcode(ERRCODE_PROTOCOL_VIOLATION),
> > + errmsg_internal("incorrect prepare LSN %X/%X in
> > prepare message (expected %X/%X)",
> > + LSN_FORMAT_ARGS(prepare_data.prepare_lsn),
> > + LSN_FORMAT_ARGS(remote_final_lsn))));
> >
> > Without being more familiar with this code, it's difficult for me to
> > judge exactly how many of such cases are in these patches.
>
> Thanks for the above example. I will fix this one later, after
> receiving some more reviews and reports of other Assert cases just
> like this one.
>

I think on similar lines below asserts also need to be changed.

1.
+static void
+apply_handle_begin_prepare(StringInfo s)
+{
+ LogicalRepPreparedTxnData begin_data;
+ char gid[GIDSIZE];
+
+ /* Tablesync should never receive prepare. */
+ Assert(!am_tablesync_worker());

2.
+static void
+TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid, int szgid)
+{
..
+ Assert(TransactionIdIsValid(xid));

3.
+static void
+apply_handle_stream_prepare(StringInfo s)
+{
+ int nchanges = 0;
+ LogicalRepPreparedTxnData prepare_data;
+ TransactionId xid;
+ char gid[GIDSIZE];
+
..
..
+
+ /* Tablesync should never receive prepare. */
+ Assert(!am_tablesync_worker());

--
With Regards,
Amit Kapila.