high interrupts on network load

[Jason Matthews]

I have a pair systems running relayd in DSR mode. The load balancer works
well, to a point, but suffers from high interrupts and cpu utilization on
eight cores. The monitoring systems show increased latency until it falls
over dead at round 330k requests/sec where the CARP seems to stop
responding and the partner jumps in only to wash-rinse-repeat the cycle.

top -aSCHIP shows 85-90% CPU utilization due to interrupts when running
near peak.

What can be done to lower the interrupt load? Or spread it across more
CPUs? Is the design such that one core is dedicated to a queue on the card?
Or can the load be spread across more CPUs?

The systems are Intel S5520UR boards with a X540-AT2 card on X5650 CPUs.

Any suggestions are appreciated.

thanks,
j.


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=  Internet =
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     |
     ix0
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=    relayd =
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     |
    ix1
     |
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- web servers -
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