Re: Cascade streaming replication + wal_files - Pgsql 9.2

On 7/6/2016 7:10 PM, Patrick B wrote:
> I'll archive the wal_files locally on slave01, and then send them to
> slave02 every 10 minutes, for example. This will be done by rsync or
> something else.
>
> I'll have still the problem with timeline, and slave02 won't be able
> to become a master in the future.
>

the master should archive to a file server (NFS or whatever). all slaves
should use this wal archive as a 'catch up source' when they resume
after downtime. [*]

master /also/ sends streaming replication to any direct attached slaves,
and those slaves can send streaming replication to any cascaded slaves,
repeat.

copying WAL archives around via rsync just seems cray-cray to me.

[*] in the latest version, there are 'replication slots' which provides
a completely different mechanism for this catch-up that doesn't require
WAL archiving

--
john r pierce, recycling bits in santa cruz