Re: WAL log archival on standby

On Fri, 19 Jun 2015 13:46 Michael Paquier <michael(dot)paquier(at)gmail(dot)com> wrote:

On Fri, Jun 19, 2015 at 2:38 PM, James Sewell <james(dot)sewell(at)lisasoft(dot)com>
wrote:

Hey All,

Is it possible to create WAL archive files on standby servers when using
streaming replication?

Yes and no, standbys do not archive WAL in ~9.4, but you could use
archive_mode = 'always' with the upcoming 9.5.

I know I can use archive_command or pg_receivexlog - but these will both
result in me sending information to the standby servers which has already
been sent via standard streaming replication. This would result in a
doubling of my network traffic.

Ideally I'd prefer to conserve this bandwidth and write the files to a
local archive on any active standby.

Both methods you mentioned are the way to go for now I am afraid, or you
wait for 9.5.

I have not tried it yet but should be possible to use pg_receivexlog from
the standby. If I can use standby server to create a streaming replica and
with pg_basebackup it should be possible to stream wal for archiving too.

Regards
Sameer