Message-Id: <4F04498F020000250004438B@gw.wicourts.gov>
Date: Wed, 04 Jan 2012 12:43:59 -0600
From: "Kevin Grittner" <Kevin.Grittner@wicourts.gov>
To: "pgsql-admin" <pgsql-admin@postgresql.org>,
	"Benjamin Krajmalnik" <kraj@servoyant.com>
Subject: Re: Problem with pgstat timeouts
References: <F4E6A2751A2823418A21D4A160B689888CA5A0@fletch.stackdump.local>
	<F4E6A2751A2823418A21D4A160B689888CA623@fletch.stackdump.local>
In-Reply-To: <F4E6A2751A2823418A21D4A160B689888CA623@fletch.stackdump.local>
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=22Benjamin Krajmalnik=22 <kraj=40servoyant.com> wrote:
=20
> Default Cache Policy: WriteBack, ReadAhead, Direct, No Write Cache
>   if Bad BBU
> Current Cache Policy: WriteThrough, ReadAhead, Direct, No Write
>   Cache if Bad BBU
=20
> Is it possible that the WriteThrough is what is causing the high
> io (and maybe the pgstat wait timeouts as well)?
=20
Yes.
=20
> If this is the case, would it be safe to change the cache to Write
> back?
=20
Maybe.  How did it get into this (non-default) state?  Are batteries
installed and healthy?
=20
> Additionally, and somewhat unrelated, is there anything special
> which I need to do when restarting the primary server vis-=E0-vis
> the streaming replication server?  In other words, if I were to
> restart the main server, will the streaming replication server
> reconnect and pick up once the primary comes online?
=20
I think that should be pretty automatic as long as you haven=27t
promoted the standby to be the new master.
=20
-Kevin