Re: Performance testing

["Brian Jackson" <brian-lists@xxxxxxxx>]

Sorry, I knew I should have sent more. 

I am using LVS-DR all on the some network director has one NIC. 

the director:
Slackware 8
kernel 2.4.19(RML's preempt kernel/lock break patches)
300Mhz K6-2
128MB RAM 

the client was pretty much the same as the director 

The Realservers
Slackware 8
kernel 2.4.19(RML's preempt kernel/lock break patches)
233Mhz K6
128MB RAM 

Maybe we could come up with like a template for people to fill out when 
sending to the list so they will send enough information for people to work 
with. That would help for cases like mine and for people asking for help. 
Just an idea. Let me know if you have any other questions. 

--Brian Jackson 

Roberto Nibali writes: 

> Hi, 
>
> Brian Jackson wrote:
> > Just as a little experiment, since I have enjoyed my preemptible/low 
> > latency patches, I decided to test my lvs cluster with the patches. The 
> > results were interesting.
> Preemptible kernels don't buy you anything on a server, it's simply 
> speaking for a desktop machine where you'd like to listen to mp3 
> (non-skipping of course) and compile the kernel. Low latency interferes 
> with the concept of preemptible kernels in that of the network stack runs 
> in softirqs and get's worked around by the kernel scheduler. If your 
> driver generates a lot of IRQs for RX buffer dehooking, the scheduler must 
> be invoked to get those packets pushed in the TCP stack or you loose 
> packets. As long as you don't run X and some number crunching software on 
> the RS preemtible kernels hurt TCP/IP stack performance IMHO. 
>
> > 1 director
> > 2 realservers
> > 1 client
> > all fast eth
> > 3com dual speed hub(I am trying to get ahold of a switch to test with)
> > I used Julian's LVS testing utilities
> > LVS without Prempt patch
> > AVG. packets/sec
> > RS1        RS2
> > 5359        5358
> > LVS with Preempt and lock-break patches from Robert Love
> > Avg. packets/sec
> > RS1        RS2
> > 4677        4675
> If you do tests, you need to give the community more information about:
> o exact kernel (vanilla + all patches, .config)
> o machine: CPU, mainboard, RAM, PCI-slot speed
> o network topology and involved HW
> o /proc/sys/net/ipv4/* settings
> o /proc/sys/net/ipv4/vs/* settings 
>
> > I didn't know if anybody would be interested in these numbers.
> People certainly are interested in performance wise evaluations of LVS but 
> with a more detailed test bed. As Julian suggested you could try NAPI or 
> TSO (kernel 2.5.x and the right NIC driver) 
>
> > Let me what you think or if you have any questions.
> > --Brian Jackson
> Thank you for the numbers. Interesting to see would also be: 
>
> o how much free idle and CPU time the machines have under load test
> o cat /proc/slabinfo
> o vmstat
> o ratio of 'TX/RX packet' rate ---> lost packets in % 
>
> Best regards,
> Roberto Nibali, ratz
> --
> echo '[q]sa[ln0=aln256%Pln256/snlbx]sb3135071790101768542287578439snlbxq' 
> | dc 
>
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