Long ParNew Collection Time

[Chi Ho Kwok]

You have vmstat installed? How about sar? sar -B [-f /var/log/sysstat/sa10]
and scan the majflt/s column, it should hover around zero, but before the
adjustment of vm.swappiness, it was in the hundreds on a "bad GC".

On Tue, Jan 11, 2011 at 2:25 PM, Shay Banon <kimchy at gmail.com> wrote:

>  I ran vmstat and did not see any swap going on (si/s0 are 0, swap is 0),
> are you suggesting that it might still be swapping?
>
> On Tuesday, January 11, 2011 at 3:21 PM, Chi Ho Kwok wrote:
>
> On Tue, Jan 11, 2011 at 2:05 PM, Shay Banon <kimchy at gmail.com> wrote:
>
>   I will give it a go. Are you suggesting that its just a time reporting
> problem, and there is no actual long GC? It does correlate with the system
> hanging and not doing anything during that time (not responding to any
> requests from clients).
>
> -shay.banon
>
>
> Did you set vm.swappiness = 0 in sysctl? Linux tends to swap out inactive
> regions of RAM, which takes forever to swap in again if the garbage
> collector touches that area after a while. free -m must show swap used at
> near zero, otherwise you're the victim of pro active swapping.
>
> Chi Ho Kwok
>
>
>
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