Re: Switch pg_basebackup to use -X stream instead of -X fetch by default?

On Tue, Aug 26, 2014 at 6:51 PM, Andres Freund <andres(at)2ndquadrant(dot)com> wrote:
> On 2014-08-26 18:40:27 +0200, Magnus Hagander wrote:
>> On Mon, Aug 25, 2014 at 1:35 PM, Andres Freund <andres(at)2ndquadrant(dot)com> wrote:
>> > Hi,
>> >
>> > currently pg_basebackup uses fetch mode when only -x is specified -
>> > which imo isn't a very good thing to use due to the increased risk of
>> > not fetching everything.
>> > How about switching to stream mode for 9.5+?
>>
>> I think the original reasons were to not change the default behaviour
>> with a new feature, and secondly because defaulting to -X requires two
>> replication connections rather than one.
>
> Right.
>
>> I think the first reason is gone now, and the risk/damage of the two
>> connections is probably smaller than running out of WAL.
>
> Especially as that will fail pretty nearly immediately instead at the
> end of the basebackup...

Yeah, I don't think the problem was actually pg_basebackup failing as
much as pg_basebackup getting in the way of regular replication
standbys. Which I think is also a smaller problem now, given that it's
a more "common thing" to do backups through replication protocol.

--
Magnus Hagander
Me: http://www.hagander.net/
Work: http://www.redpill-linpro.com/