Thread: about synchronous_standby_names or sync replic

about synchronous_standby_names or sync replic

From
e-blokos
Date:
Hi Folks,

I wonder if it's possible to have a sync replication only from the the node
where the client
who update the DB and other node replicated asynchronously ?

example :
nodeCentral node1 node2 node3

user1  from node3 update db to nodeCentral (master) so nodeCentral
replicates synchronously node3 and later other nodes...

sorry if my question is irrelevant at this time ;)

Thanks

Franck

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Re: about synchronous_standby_names or sync replic

From
Jaime Casanova
Date:
On Thu, Sep 22, 2011 at 2:34 PM, e-blokos <infos@e-blokos.com> wrote:
> Hi Folks,
>
> I wonder if it's possible to have a sync replication only from the the node
> where the client
> who update the DB and other node replicated asynchronously ?
>
> example :
> nodeCentral node1 node2 node3
>
> user1  from node3 update db to nodeCentral (master) so nodeCentral
> replicates synchronously node3 and later other nodes...
>

yep, put the names of all the nodes in synchronous_standby_names and
set synchronous_commit to local... then when someone sends a write
command to the server "set synchronous_commit to on" (of course, this
SET is a command you send to the server just like any other SQL
command)

don't forget to reset synchronous_commit or use set local, otherwise
you will let this node as the sync rep until disconnect

--
Jaime Casanova         www.2ndQuadrant.com
Professional PostgreSQL: Soporte 24x7 y capacitación

Re: about synchronous_standby_names or sync replic

From
"E-Blokos"
Date:
Thanks for your answer.
That's great,
so for later other nodes replication it
needs an asynchronous replic like pg_stat or even a good old rsync ?

Franck

----- Original Message -----
From: "Jaime Casanova" <jaime@2ndquadrant.com>
To: "e-blokos" <infos@e-blokos.com>
Cc: <pgsql-general@postgresql.org>
Sent: Thursday, September 22, 2011 11:38 PM
Subject: Re: [GENERAL] about synchronous_standby_names or sync replic


On Thu, Sep 22, 2011 at 2:34 PM, e-blokos <infos@e-blokos.com> wrote:
> Hi Folks,
>
> I wonder if it's possible to have a sync replication only from the the
> node
> where the client
> who update the DB and other node replicated asynchronously ?
>
> example :
> nodeCentral node1 node2 node3
>
> user1 from node3 update db to nodeCentral (master) so nodeCentral
> replicates synchronously node3 and later other nodes...
>

yep, put the names of all the nodes in synchronous_standby_names and
set synchronous_commit to local... then when someone sends a write
command to the server "set synchronous_commit to on" (of course, this
SET is a command you send to the server just like any other SQL
command)

don't forget to reset synchronous_commit or use set local, otherwise
you will let this node as the sync rep until disconnect

--
Jaime Casanova www.2ndQuadrant.com
Professional PostgreSQL: Soporte 24x7 y capacitación


Re: about synchronous_standby_names or sync replic

From
"E-Blokos"
Date:
Mmmh sorry for my ignorance,
I just learnt that PG 9.0 includes a built in replication.
My first PG install was in 1998, what a pleasure how
PG became today...

long life to PG community

Franck

----- Original Message -----
From: "Jaime Casanova" <jaime@2ndquadrant.com>
To: "e-blokos" <infos@e-blokos.com>
Cc: <pgsql-general@postgresql.org>
Sent: Thursday, September 22, 2011 11:38 PM
Subject: Re: [GENERAL] about synchronous_standby_names or sync replic


On Thu, Sep 22, 2011 at 2:34 PM, e-blokos <infos@e-blokos.com> wrote:
> Hi Folks,
>
> I wonder if it's possible to have a sync replication only from the the
> node
> where the client
> who update the DB and other node replicated asynchronously ?
>
> example :
> nodeCentral node1 node2 node3
>
> user1 from node3 update db to nodeCentral (master) so nodeCentral
> replicates synchronously node3 and later other nodes...
>

yep, put the names of all the nodes in synchronous_standby_names and
set synchronous_commit to local... then when someone sends a write
command to the server "set synchronous_commit to on" (of course, this
SET is a command you send to the server just like any other SQL
command)

don't forget to reset synchronous_commit or use set local, otherwise
you will let this node as the sync rep until disconnect

--
Jaime Casanova www.2ndQuadrant.com
Professional PostgreSQL: Soporte 24x7 y capacitación