[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.


Joseph Mack NA3T EME(B,D), FM05lw North Carolina
jmack (at) wm7d (dot) net - azimuthal equidistant map
generator at http://www.wm7d.net/azproj.shtml
Homepage http://www.austintek.com/ It's GNU/Linux!

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