Troubleshooting a ~40-second minor collection

[Aaron Daubman]

Hi Bernd,

Thanks for the info.
This is a numa machine, however, as part of setting up hugepages, I have
disabled numa (numa=off) in grub.conf (and have also disabled transparent
huge page support).

The JVM process is the only significant process (aside from the high-rate
data copy tar/nc/pigz) running on this 32-core, 2-node 64G RAM box. The tar
process is limited to using one CPU (close to 100%) but leaving 31 others
free for the JVM - load average on the box is fairly low.

The JVM process is spread fairly evenly over the nodes - watching htop I
can see CPU jumping around among the 32 cores.

Do you know what I might look at to see network/disk driver missbehavior?

Thanks!
    Aaron


On Mon, Dec 2, 2013 at 5:21 PM, Bernd Eckenfels <bernd-2013 at eckenfels.net>wrote:

> Hello Aaron,
>
> another rough guess is, that when you "copy high rate" that you have a lot
> of system interrupt time and conext switches (especially when the network
> or disk drivers are missbehaving).
>
> I wonder if if this can really slow down the GC so much, but it would be
> the next thing I would investigate.
>
> Is this a NUMA machine? Is the JVM process spread over multiple nodes?
>
> Gruss
> Bernd
>
>
> Am 02.12.2013, 23:14 Uhr, schrieb Aaron Daubman <daubman at gmail.com>:
>
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