Re: Setting up streaming replication with new server as master?

On Wed, Feb 17, 2016 at 10:02 AM, Dave Johansen <davejohansen(at)gmail(dot)com>
wrote:

> On Sat, Feb 6, 2016 at 6:38 PM, John Scalia <jayknowsunix(at)gmail(dot)com>
> wrote:
>
>> If you specify -X f or more likely -X s, that will cause pg_basebackup to
>> include the WAL files that were written after you started the operation.
>> Since you're setting up a replica, use the -X s option as that's for
>> streaming.
>>
>
> I ran pg_basebackup with -X s and it finished in the middle of the night
> last night. I would now like to make the switch, but what's the best way to
> copy over the records that have been inserted since the backup stopped?
>

The -Xs option just keeps the WAL files that were written during the backup
run so that if you restore it, it's brought back up to a consistent state
at the point when the backup itself finished.

If you want to be able to bring up a slave from a backup at any point after
that backup was complete, you have to keep all the WAL files that have been
written since then. This is what is called Point-In-Time Recovery (PITR). I
highly recommend you read up on the docs for how WAL files in postgres work
and how to use them with backups and slaves. I think that is a key point
your missing in understanding how to get a streaming slave set up and
working.

http://www.postgresql.org/docs/9.5/static/continuous-archiving.html