[Spread-users] Story for sysadmin magazine

[Jonathan Stanton]

On Fri, Oct 04, 2002 at 06:33:20PM -0400, George Schlossnagle wrote:
> I've had so many issues with the multicast idiosynchrocies that I've 
> stopped using multicast mode in all the production apps I touch.  It 
> just seems to sensitive to obscure breakages.  Yair or someother cnds 
> person may take exception to that, and with an IGMP-snooping switch 
> there are definite bandwidth benefits to using multicast, but it does 
> seem a bit.... persnickety on many platforms.

I don't think any of us here at CNDS would disagree with anyone calling
multicast "persnickety" 

We have had it work successfully on some platforms and in some network
configurations, but we have also had routing problems, strange performance
problems with some switches, and found it very difficult to use on
machines with multiple interfaces. 

I'd definitely recommend using broadcast for starter configurations, and
trying out the multicast option if broadcast proves to cause too much load
on other machines, or if several different spread configurations are being
run on the same switch and you want to maximize performance for all of
them.

Jonathan

P.S. I'm really happy to hear about your article, I thought it was well
written and covered the topic well. 

-- 
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Jonathan R. Stanton         jonathan at cs.jhu.edu
Dept. of Computer Science   
Johns Hopkins University    
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