massive load average spikes

[Julian Elischer]

On 8/11/10 11:56 AM, markham breitbach wrote:
>
>
> On 11/08/10 11:59 AM, Chuck Swiger wrote:
>> Hi--

[...]

>
> Sorry for the limited data, It's hard to know where to draw the line between useful data
> and information overload, but I'm more than happy to supply whatever other info you might
> find useful.
>
> I did take a look at my dovecot logs, and there are not more than a couple of failed auth
> attempts in any given minute.  Sendmail logs don't show any excessive activity when LA
> spikes either.
>
> "vmstat -w1" shows occasional  spikes of processes in the run queue, but that doesn't
> usually correlate to spikes in load average (although sometimes it is close).

[...]

>

load average is a time averaged thing and in the case of a
'thundering herd' problem you will see the LA spike up and
come down again over time.

Do you see any problem as a result of this? Or is it just curiosity?

you might want to use KTR or ktrace with scheduling events if you
really want to see the reason for this. It could just be a sampling
error when some 'tick' coincides with the sampling..


>
> Wed Aug 11 12:40:55 MDT 2010
>      0.60     3.38     3.79
>      0.60     3.38     3.79
>      0.55     3.33     3.77
>      0.55     3.33     3.77
>      0.55     3.33     3.77
>      0.55     3.33     3.77
>     40.94    11.66     6.70
>     40.94    11.66     6.70
>     40.94    11.66     6.70
>     40.94    11.66     6.70
> Wed Aug 11 12:41:05 MDT 2010
>     40.94    11.66     6.70
>     40.94    11.66     6.70
>     37.67    11.46     6.66
>     37.67    11.46     6.66
>     37.67    11.46     6.66
>     37.67    11.46     6.66
>     37.67    11.46     6.66
>     34.65    11.27     6.63
>     34.65    11.27     6.63
>     34.65    11.27     6.63
>
>
>
>