Re: [BUG] Checkpointer on hot standby runs without looking checkpoint_segments

Fujii Masao <masao.fujii@gmail.com>

From: Fujii Masao <masao.fujii@gmail.com>
To: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>
Cc: heikki.linnakangas@enterprisedb.com, pgsql-hackers@postgresql.org
Date: 2012-04-18T17:02:24Z
Lists: pgsql-hackers
On Wed, Apr 18, 2012 at 10:22 AM, Kyotaro HORIGUCHI
<horiguchi.kyotaro@lab.ntt.co.jp> wrote:
> I tried that at first. But I suppose the requirement here is 'if
> reading segments comes via replication stream, enable throttling
> by checkpoint_segments.' and WalRcvInProgress() seems fit to
> check that.

If so, what if replication is terminated and restarted repeatedly while
a restartpoint is running? It sometimes obeys and sometimes ignores
checkpoint_segments. Which seems strange behavior.

> Plus, adding SharedStartupStandbyMode into
> XLogCtlData seems accompanied with some annoyances which would
> not pay.

Hmm... what are you worried about? I don't think that sharing the variable
via XLogCtl is so difficult. Please see the code to share archiveCleanupCommand
from the startup process to the checkpointer. It looks very simple.

> By the way, do you have some advise about GetStandbyFlushRecPtr()
> and the order of the locations? I'm embarrassed with that...

Sorry. I could not parse this.... Could you explain this again?

Regards,

-- 
Fujii Masao