> On Jan 20, 2017, at 7:03 PM, bto...@computer.org <bto...@broadstripe.net> > wrote: > > While learning a bit about basic hot standby configuration, I was reviewing > an article that used these parameters > > wal_level = 'hot_standby' > archive_mode = on > archive_command = 'cd .' > max_wal_senders = 1 > hot_standby = on > > > How or why that particular archive_command actually works (... and it does > ... I tried it ...) is not clear to me based on reading of the Postgresql > documentation on this topic. I would have expected to see an actual copy or > rsync command, as described in the fine manual at section 25.3.1. "Setting Up > WAL Archiving" > > The entire example appears at > > https://www.digitalocean.com/community/tutorials/how-to-set-up-master-slave-replication-on-postgresql-on-an-ubuntu-12-04-vps > > Can anyone enlighten on this topic, or provide a link to an existing > explanation?
It's not archiving logs at all, instead relying on streaming them directly to the slave. Changing archive_mode requires a server restart, while changing archive_command from a command that does nothing, successfully, to a command that actually archives logs just requires a reload. So this lets you enable archiving without halting the server by changing the command. Or that's how I vaguely recall it working some years ago. Things may have changed now - you're following a very old tutorial. Cheers, Steve -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
