Re: Re: [COMMITTERS] pgsql: Make standby server continuously retry restoring the next WAL
Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
From: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
To: Simon Riggs <simon@2ndQuadrant.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Fujii Masao <masao.fujii@gmail.com>, Aidan Van Dyk <aidan@highrise.ca>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2010-03-25T10:26:25Z
Lists: pgsql-hackers
Simon Riggs wrote: > On Thu, 2010-03-25 at 10:11 +0200, Heikki Linnakangas wrote: > >> PANIC seems like the appropriate solution for now. > > It definitely is not. Think some more. Well, what happens now in previous versions with pg_standby et al is that the standby starts up. That doesn't seem appropriate either. Hmm, it would be trivial to just stay in the standby mode at a corrupt file, continuously retrying to restore it and continue replay. If it's genuinely corrupt, it will never succeed and the standby gets stuck at that point. Maybe that's better; it's close to what Fujii suggested except that you don't need a new mode for it. I'm worried that the administrator won't notice the error promptly because at a quick glance the server is up and running, while it's actually stuck at the error and falling indefinitely behind the master. Maybe if we make it a WARNING, that's enough to alleviate that. It's true that if the standby is actively being used for read-only queries, shutting it down to just get the administrators attention isn't good either. -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com