[Bucardo-general] Bucardo Postgres Replication from Master to Slave Read Only Replica

[jay saini]

Hi David,

The use case here is that we have 2 Clusters. One Cluster is on AWS Aurora
Postgres Compatible Version 11.6 which has master and slave rds instance.
Master is writable DB and Slave is read-only DB. We want to use Bucardo to
replicate the slave DB ( read-only) to the Cluster on Google CloudSQL which
is also Postgres 12 compatible DB and is Writable. We donot want much
transactions on master hence want to use aurora read replica which is slave
to act as source and google cloudsql db to act as destination.

Let me know your thoughts on this and if it's possible or not.

Regards
Jaydeep

On Fri, Oct 16, 2020 at 9:14 PM David Christensen <david at endpoint.com>
wrote:

> Hi Jay,
>
> Bucardo uses triggers to capture data changes (and clean up after itself)
> so it has to run on a writeable server.
>
> What is the use case you’re looking at, and what are the versions of the
> databases involved?
>
> Best,
>
> David
> --
> David Christensen
> Senior Software and Database Engineer
> End Point Corporation
> david at endpoint.com
> 785-727-1171
>
>
> > On Oct 16, 2020, at 10:35 AM, jay saini <jay00725 at gmail.com> wrote:
> >
> > Hi David,
> >
> > Thanks for your reply. I have tested both the writable dbs and it works
> fine for me. The use case is to use read only replica (slave) which will
> act as source and replicate it to writable db? Is this possible with
> Bucardo? Or we need to have both the dbs as Writable.
> >
> > Expecting your response on this.
> >
> > Regards
> > Jaydeep
> >
> > On Fri, 16 Oct 2020 at 8:09 PM, David Christensen <david at endpoint.com>
> wrote:
> > Hi Jay,
> >
> > You need to target a writable database since it is trying to insert
> rows; you can’t use a readonly standby for the target. Could you use the
> source for the readonly standby as the target?
> >
> > Best,
> >
> > David
> >
> >> On Oct 16, 2020, at 8:26 AM, jay saini <jay00725 at gmail.com> wrote:
> >>
> >> 
> >> I have successfully performed replication from Master to Master from
> Bucardo. I am stucked in Master-Slave replication. When I am trying to add
> a sync it gives me the following error:
> >>
> >> root at ip-172-31-XX-XX:~# bucardo add sync test relgroup=herd_pg
> dbs=SRC,DEST_SLAVE
> >>
> >> WARNING: Issuing rollback() due to DESTROY without explicit
> disconnect() of DBD::Pg::db handle
> dbname=migratedb;host=35.243.157.109;port=5432 at line 207. Failed to add
> sync: DBD::Pg::st execute failed: ERROR: DBD::Pg::db do failed: ERROR:
> cannot set transaction read-write mode during recovery at line 207. at line
> 30. CONTEXT: PL/Perl function "validate_sync" at /usr/bin/bucardo line 4670.
> >>
> >> To give you more context: My master is AWS Aurora Postgres RDS and My
> slave is on Google CloudSQL which is a read-only replica.
> >>
> >> Looking forward for response
> >> _______________________________________________
> >> Bucardo-general mailing list
> >> Bucardo-general at bucardo.org
> >> https://bucardo.org/mailman/listinfo/bucardo-general
>
>
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