Re: Logical replication from PG v13 and below to PG v14 (devel version) is not working. - Mailing list pgsql-hackers

From Ashutosh Sharma
Subject Re: Logical replication from PG v13 and below to PG v14 (devel version) is not working.
Date
Msg-id CAE9k0P=u8i-WYw2Scowx8FJtLFuZ3urwPVnYRnahy+TgLgzP1Q@mail.gmail.com
Whole thread Raw
In response to Re: Logical replication from PG v13 and below to PG v14 (devel version) is not working.  (Amit Kapila <amit.kapila16@gmail.com>)
Responses Re: Logical replication from PG v13 and below to PG v14 (devel version) is not working.  (Amit Kapila <amit.kapila16@gmail.com>)
List pgsql-hackers
Hi Amit,

On Thu, Sep 24, 2020 at 11:55 AM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> On Tue, Sep 22, 2020 at 5:15 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
> >
> > On Tue, Sep 22, 2020 at 12:02 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
> > >
> > >
> > > I am not sure if this suggestion makes it better than what is purposed
> > > by Dilip but I think we can declare them in define number order like
> > > below:
> > > #define LOGICALREP_PROTO_MIN_VERSION_NUM 1
> > > #define LOGICALREP_PROTO_VERSION_NUM 1
> > > #define LOGICALREP_PROTO_STREAM_VERSION_NUM 2
> > > #define LOGICALREP_PROTO_MAX_VERSION_NUM LOGICALREP_PROTO_STREAM_VERSION_NUM
> >
> > Done this way.
> >
>
> - options.proto.logical.proto_version = LOGICALREP_PROTO_VERSION_NUM;
> + options.proto.logical.proto_version = MySubscription->stream ?
> + LOGICALREP_PROTO_STREAM_VERSION_NUM : LOGICALREP_PROTO_VERSION_NUM;
>
> Here, I think instead of using MySubscription->stream, we should use
> server/walrecv version number as we used at one place in tablesync.c.

Should subscribers be setting the LR protocol value based on what is
the publisher version it is communicating with or should it be set
based on whether streaming was enabled or not while creating that
subscription? AFAIU if we set this value based on the publisher
version (which is lets say >= 14), then it's quite possible that the
subscriber will start streaming changes for the in-progress
transactions even if the streaming was disabled while creating the
subscription, won't it?

Please let me know if I am missing something here.

Thanks,

-- 
With Regards,
Ashutosh Sharma
EnterpriseDB:http://www.enterprisedb.com



pgsql-hackers by date:

Previous
From: Amit Kapila
Date:
Subject: Re: Resetting spilled txn statistics in pg_stat_replication
Next
From: Hamid Akhtar
Date:
Subject: Re: fixing old_snapshot_threshold's time->xid mapping