Brendan,
If you are doing this via nfs, you should be sure that mounts are
done using the tcp parameter in /etc/fstab. Otherwise you may get
udp, and I have seen problems with that as recently as Fedora 8 this morning!
Mike
At 08:03 PM 12/17/2007, Brendan Moloney wrote:
I have a cluster of 8 Linux machines connected with gigabit ethernet
(full duplex) to a HP Procurve 2848 switch. I am using the
machines to do interactive distributed rendering. I have noticed
that the final gather stage (where the intermediate images from the
render nodes are sent back to the viewing node) has "hiccups" in the
performance. These hiccups occur with as few as two render nodes,
and become more common as I add more render nodes. With a 512x512
image the final gather usually takes a few milliseconds for each
frame, but when the hiccups occur it is more like 200+ milliseconds.
Since it is a full duplex switched network, there should not be any
collisions happening. Since the image is less than 1 MB total, I
don't think I am saturating the switch. I have checked the contents
of /sbin/ifconfig and there are zero erroneous packets being
reported. At this point I am really at a loss as to what is causing
this. Any input on things to check would be greatly appreciated.
Thanks,
Brendan
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