Re: Can master and slave on different PG versions?

From Slave (9.6):

Database cluster state: shut down in recovery
wal_level setting: logical

From master (9.4) :

Database cluster state: in production
Current wal_level setting: logical

Quite frankly i couldn't find proper document on how to set logical
replication in 9.4, i think i am using pg_logical. All i did was set
wal_level to logical and add primary_slot_name in recovery.conf. Do i need
to install pglogical extension? i couldn't find one for amazon linux.

Thanks,
Ram

On Thu, Nov 16, 2017 at 6:12 AM, <gparc(at)free(dot)fr> wrote:

>
> Hello again,
>
> can you execute pg_controldata command on both Master and Slave
> and check the following properties :
> Database cluster state
> wal_level setting
>
> Also, if I understand correctly, you want to establish logical replication
> between your 9.4 master
> and your 9.6 slave but you don't explain how ? using pg_logical ?
>
> Regards
>
> ----- Mail original -----
> De: "rammohan ganapavarapu" <rammohanganap(at)gmail(dot)com>
> À: "David G. Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com>
> Cc: pgsql-admin(at)postgresql(dot)org
> Envoyé: Mercredi 15 Novembre 2017 22:23:57
> Objet: Re: [ADMIN] Can master and slave on different PG versions?
>
>
> Any one tried this before?
>
>
> On Wed, Nov 8, 2017 at 8:17 AM, rammohan ganapavarapu <
> rammohanganap(at)gmail(dot)com > wrote:
>
>
>
> David,
>
>
> So initially i have physical replication configured, so to upgrade slave
> to 9.6 version i did converted master slave to logical replication and then
> try to upgrade the slave to 9.6. I am getting this error when i try to
> start the slave. Any idea?
>
>
>
>
>
> 2017-11-08 05:08:49 UTC [20063]: [1-1] user= db= host= LOG: shutting down
> 2017-11-08 05:08:49 UTC [20063]: [2-1] user= db= host= LOG: database
> system is shut down
> 2017-11-08 05:09:45 UTC [20322]: [1-1] user= db= host= LOG: database
> system was shut down at 2017-11-08 05:08:55 UTC
> 2017-11-08 05:09:45 UTC [20322]: [2-1] user= db= host= LOG: entering
> standby mode
> 2017-11-08 05:09:45 UTC [20322]: [3-1] user= db= host= WARNING: WAL was
> generated with wal_level=minimal, data may be missing
> 2017-11-08 05:09:45 UTC [20322]: [4-1] user= db= host= HINT: This happens
> if you temporarily set wal_level=minimal without taking a new base backup.
> 2017-11-08 05:09:45 UTC [20322]: [5-1] user= db= host= FATAL: hot standby
> is not possible because wal_level was not set to "replica" or higher on the
> master server
> 2017-11-08 05:09:45 UTC [20322]: [6-1] user= db= host= HINT: Either set
> wal_level to "replica" on the master, or turn off hot_standby here.
> 2017-11-08 05:09:45 UTC [20312]: [3-1] user= db= host= LOG: startup
> process (PID 20322) exited with exit code 1
> 2017-11-08 05:09:45 UTC [20312]: [4-1] user= db= host= LOG: aborting
> startup due to startup process failure
> 2017-11-08 05:09:45 UTC [20312]: [5-1] user= db= host= LOG: database
> system is shut down
>
>
> Thanks,
> Ram
>
>
>
>
>
>
>
>
> On Mon, Oct 9, 2017 at 4:15 PM, David G. Johnston <
> david(dot)g(dot)johnston(at)gmail(dot)com > wrote:
>
>
>
>
> On Mon, Oct 9, 2017 at 4:06 PM, rammohan ganapavarapu <
> rammohanganap(at)gmail(dot)com > wrote:
>
>
>
>
>
> Hi,
>
>
> Is it possible to add 9.6 version Slave to 9.4 master?
>
>
>
>
> ​Physical replication, no; Logical replication, yes - if the software you
> are using is compatible with both versions.
>
>
> David J.​
>
>