[lvs-users] Are LVS / ldirectord Multithreaded?

Joseph Mack NA3T jmack at wm7d.net
Fri Oct 31 21:25:10 GMT 2008


On Fri, 31 Oct 2008, Robinson, Eric wrote:

> are lvs and ldirectord multithreaded? I suspect LVS is and 
> ldirectord (being a perl script) is not.

lvs is a bunch of hooks into the linux routing/packet 
handling code. LVS is as multithreaded as the linux routing 
code. I hadn't thought about the threadedness of kernel 
code. I assume it isn't but I don't know.

I expect ldirectord isn't multithreaded. It doesn't have to 
be fast.

> We have a load balancer that is working pretty hard. It's 
> a single-core Celeron 2.4GHz machine with 512MB RAM. It 
> runs about 40-70% CPU utilization on average, with peaks 
> to 99%. If I replace it with a dual-core machine, will the 
> load balancing process benefit from multiple cores?

this is in the HOWTO. LVS doesn't benefit from multiple CPUs 
(or it didn't last we looked)

This is a fairly hefty load. I didn't think that packet 
pushing could do this. What sort of packet throughput are 
you getting? Are you using LVS-DR or LVS-NAT? Is the 
director doing anything else as well? Some nics are better 
at handling the packets on-board, but I don't know what they 
are. Have you looked into getting the best nics? From 
postings on this list you should avoid Broadcom. Some people 
like Intel.

Joe

-- 
Joseph Mack NA3T EME(B,D), FM05lw North Carolina
jmack (at) wm7d (dot) net - azimuthal equidistant map
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