[LARTC] Best regards from a clueless soul with a problem...

[LARTC] Best regards from a clueless soul with a problem...

[Carlo E. Prelz]

Hello collective wisdom. I am finding myself in this situation:

one machine with two netcards. One talking to the outside (cheap
100MB), and one, an Intel E1000 card, connected with a crossover cable
to another Linux PC that has to receive multicast UDP packets at the
possibly highest rate. The traffic is 99.999% one-way.

In the constant search for better performance I decided to buy these
two gigabit ethernet cards, expecting, if not a 10-time increase in
performance, at least some visible improvement. I seeonly marginal
improvement if compared with a 100Mb set of cards plus switch. (the
connection is confirmed as 1000MB full duplex on both sides)

I have been searching for the bottleneck: the blovking calls to
'sendto' suck up almost all time. I have an average CPU idle rate of
95%. OTOH, talking to the machine on the other end of the cable via
SSH is very smooth: something that should not happen if my main
process were occupying all possible bandwidth.

It came to me that maybe this mysterious traffic control set of kernel
modules and utilities could also be used to guarantee to one process
a particularly high chunk of bandwidth on a specific channel. But the
material I can find is mind-boggingly complex, with dozens of
parameters and a whole new world of terminology. before I invest more
in this path, I decided to ask you all if I am barking up the wrong
tree... Whatever advice is welcome. 

Thanks in advance.

Carlo

-- 
  *         Se la Strada e la sua Virtu' non fossero state messe da parte,
* K * Carlo E. Prelz - lartc@fluido.as              che bisogno ci sarebbe
  *               di parlare tanto di amore e di rettitudine? (Chuang-Tzu)
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