Re: [Extern] Re: Is a logical replication crash recovery safe?

2023-04-14 Thread GF
Markus,
Yesterday EDB published the (open source) pg_failover_slots extension,
aimed at pushing logical slot information on standbys: without it, that
information is kept on the master only, so you have to rebuild the logical
replication topology on switch/fail-overs.
Obviously, if the promoted server is outdated wrt to the lost master, you
could still have problems with subscriptions, although there some
configuration that tries to address that problem too
(standby_slots_min_confirmed).
For the moment being you can find the documentation at EDB's docs
<https://www.enterprisedb.com/docs/pg_extensions/pg_failover_slots>, and
the sources at github.com/EnterpriseDB/pg_failover_slots. I hope the
extension will make quickly its way to PGDG as prebuilt packages.
Best,
g


On Tue, 24 Jan 2023 at 17:08, Zwettler Markus (OIZ) <
markus.zwett...@zuerich.ch> wrote:

> > -Ursprüngliche Nachricht-
> > Von: Christophe Pettus 
> > Gesendet: Dienstag, 24. Januar 2023 16:48
> > An: Zwettler Markus (OIZ) 
> > Cc: pgsql-general@lists.postgresql.org
> > Betreff: [Extern] Re: Is a logical replication crash recovery safe?
> >
> >
> >
> > > On Jan 24, 2023, at 07:37, Zwettler Markus (OIZ) <
> markus.zwett...@zuerich.ch>
> > wrote:
> > >
> > > Is a logical replication crash recovery safe?
> >
> > You might want to give more detail about the scenario you are concerned
> about.
> > Changes that are received by a subscriber as part of logical replication
> are WAL-
> > logged, observe transaction semantics, and will be replayed if the
> subscriber
> > crashes and restarts.
> >
>
>
> Sorry. Let me refine.
>
> If I create a logical replication slot and use the replication slot to
> publish some tables.
>
> Will the information in the replication slot be safe for any subscription
> even if a crash recovery happened on the publisher node?
>
>
>


AW: [Extern] Re: Is a logical replication crash recovery safe?

2023-01-24 Thread Zwettler Markus (OIZ)
> -Ursprüngliche Nachricht-
> Von: Christophe Pettus 
> Gesendet: Dienstag, 24. Januar 2023 16:48
> An: Zwettler Markus (OIZ) 
> Cc: pgsql-general@lists.postgresql.org
> Betreff: [Extern] Re: Is a logical replication crash recovery safe?
> 
> 
> 
> > On Jan 24, 2023, at 07:37, Zwettler Markus (OIZ) 
> > 
> wrote:
> >
> > Is a logical replication crash recovery safe?
> 
> You might want to give more detail about the scenario you are concerned about.
> Changes that are received by a subscriber as part of logical replication are 
> WAL-
> logged, observe transaction semantics, and will be replayed if the subscriber
> crashes and restarts.
> 


Sorry. Let me refine.

If I create a logical replication slot and use the replication slot to publish 
some tables.

Will the information in the replication slot be safe for any subscription even 
if a crash recovery happened on the publisher node?




Re: Is a logical replication crash recovery safe?

2023-01-24 Thread Christophe Pettus



> On Jan 24, 2023, at 07:37, Zwettler Markus (OIZ)  
> wrote:
> 
> Is a logical replication crash recovery safe?

You might want to give more detail about the scenario you are concerned about.  
Changes that are received by a subscriber as part of logical replication are 
WAL-logged, observe transaction semantics, and will be replayed if the 
subscriber crashes and restarts.