Re: Online base backup from the hot-standby
Simon Riggs <simon@2ndquadrant.com>
From: Simon Riggs <simon@2ndQuadrant.com>
To: Fujii Masao <masao.fujii@gmail.com>
Cc: Steve Singer <ssinger_pg@sympatico.ca>, Jun Ishiduka <ishizuka.jun@po.ntts.co.jp>, magnus@hagander.net, heikki.linnakangas@enterprisedb.com, pgsql-hackers@postgresql.org, robertmhaas@gmail.com, cedric.villemain.debian@gmail.com
Date: 2012-01-25T08:49:42Z
Lists: pgsql-hackers
On Wed, Jan 25, 2012 at 8:16 AM, Fujii Masao <masao.fujii@gmail.com> wrote: >> What happens if we shutdown the WALwriter and then issue SIGHUP? > > SIGHUP doesn't affect full_page_writes in that case. Oh, you are concerned about > the case where smart shutdown kills walwriter but some backends are > still running? > Currently SIGHUP affects full_page_writes and running backends use the changed > new value of full_page_writes. But in the patch, SIGHUP doesn't affect... > > To address the problem, we should either postpone the shutdown of walwriter > until all backends have gone away, or leave the update of full_page_writes to > checkpointer process instead of walwriter. Thought? checkpointer seems the correct place to me -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services