Re: Re: [COMMITTERS] pgsql: Make standby server continuously retry restoring the next WAL
Simon Riggs <simon@2ndquadrant.com>
From: Simon Riggs <simon@2ndQuadrant.com>
To: Dimitri Fontaine <dfontaine@hi-media.com>
Cc: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>, Fujii Masao <masao.fujii@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2010-02-11T13:50:50Z
Lists: pgsql-hackers
On Thu, 2010-02-11 at 14:41 +0100, Dimitri Fontaine wrote: > Simon Riggs <simon@2ndQuadrant.com> writes: > > If you were running pg_standby as the restore_command then this error > > wouldn't happen. So you need to explain why running pg_standby cannot > > solve your problem and why we must fix it by replicating code that has > > previously existed elsewhere. > > Let me try. > > pg_standby will not let the server get back to streaming replication > mode once it's done with driving the replay of all the WAL files > available in the archive, but will have the server sits there waiting > for the next file. > > The way we want that is implemented now is to have the server switch > back and forth between replaying from the archive and streaming from the > master. So we want the server to restore from the archive the same way > pg_standby used to, except that if the archive does not contain the next > WAL files, we want to get back to streaming. > > And the archive reading will resume at next network glitch. > > I think it's the reasonning, I hope it explains what you see happening. OK, thanks. One question then: how do we ensure that the archive does not grow too big? pg_standby cleans down the archive using %R. That function appears to not exist anymore. -- Simon Riggs www.2ndQuadrant.com