Re: Cascade streaming replication + wal_files - Pgsql 9.2

On Thu, 7 Jul 2016, 9:20 a.m. Patrick B, <patrickbakerbr(at)gmail(dot)com> wrote:

> Hi guys,
>
> I got two slaves using Postgresql 9.2.
>
> slave01 - Streaming replication from master
> slave02 - nothing.. new server
>
> is it possible to get slave02 replicating from slave01 (Cascade streaming
> replication) this can be done with streaming ?
>

Yes, a cascaded standby can be setup with Streaming Replication in v9.2 and
above.

and also slave01 sending the wal_files to that new slave02?
>

What exactly do you mean here by "sending the wal_files"??

> So it would be on slave01
>
> archive_mode = ok
> archive_command = ....
>

This will have no effect on a standby server. archive_command will be
neglected

This is possible only in v9.5 onward when archive_mode is set to always.

wal_level = hot_standby
> max_wal_senders = 2
> wal_keep_segments = 128
>
> Is that right?
>

If you want to set up archiving from slave01, checkout pg_receivexlog.

https://www.postgresql.org/docs/9.2/static/app-pgreceivexlog.html

It might be helpful as it does something similar to archiving but using
streaming protocol (so I think it should work even in cascaded mode). But
since it works using streaming protocol, max_wal_senders on slave01 will be
2(what you have set now) + 1 (for pg_reveivexlog)

> Cheers guys!
> Patrick
>
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