On Fri, 11 Sep 2009, Alan McKay wrote:
Munin takes a snapshot every 5 minutes, and this graph shows it
averaged over that timeframe.
The default postgresql.conf puts a checkpoint every 5 minutes as well.
It's not going to be as exact as Munin's time though, they'll be just a
little longer th
> What's the scale on the bottom there? The label says "by week" but the way
> your message is written makes me think it's actually a much smaller time
> frame. If those valleys are around around five minutes apart, those are the
> checkpoints finishing; the shape of the graph is right for it to
On Fri, 11 Sep 2009, Alan McKay wrote:
We aren't seeing any performance problems on this per-se. But that
just seems like a really odd graph to me. Can anyone explain it? In
particular, how regular it is?
What's the scale on the bottom there? The label says "by week" but the
way your mes
Alan McKay wrote:
>> My guess is this is checkpoint related.
>
> I'll assume "checkpoint" is a PG term that I'm not yet familiar with
-
> will query my DBA :-)
A checkpoint flushes all dirty PostgreSQL buffers to the OS and then
tells the OS to write them to disk. The exact details of how t
> My guess is this is checkpoint related.
I'll assume "checkpoint" is a PG term that I'm not yet familiar with -
will query my DBA :-)
If this OS buffer cache, wouldn't that be cached an awfully long time?
i.e. we're in big trouble if we get a bad crash?
--
“Don't eat anything you've ever see
On 9/11/09 9:58 AM, "Alan McKay" wrote:
> Hey folks,
>
> Earlier in the week I wrote a Munin plugin that takes the "await" and
> "average queue length" fields from "iostat -x" and graphs them.
>
> This seems rather odd to me :
>
> http://picasaweb.google.ca/alan.mckay/Work#5380253477470243954
Hey folks,
Earlier in the week I wrote a Munin plugin that takes the "await" and
"average queue length" fields from "iostat -x" and graphs them.
This seems rather odd to me :
http://picasaweb.google.ca/alan.mckay/Work#5380253477470243954
That is Qlen. And await looks similar
http://picasaweb
