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Re: [Xen-devel] Benchmarking Xen (results and questions)

To: David_Wolinsky@xxxxxxxx
Subject: Re: [Xen-devel] Benchmarking Xen (results and questions)
From: Andrew Theurer <habanero@xxxxxxxxxx>
Date: Thu, 04 Aug 2005 10:11:37 -0500
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This is much better. I think my email client just didn't format your first (html?) message. For JBB, I suspect the degrade is mostly cache thrashing, and the increased timeslice = better cache warmth. Perhaps there a lot of overhead in the domain context switch as well. What is the cpu cache size?

I will soon be doing tests like these on a dozen or so benchmarks, so hopefully we can compare results. Have you looked at using xenoprofile while running your tests?

As for the WebBench numbers, do you have cpu utilization stats for Host and each of the domains? Is it possible the Host and 1 VM are not using much cpu at all, and adding domains/clients just increases cpu util & TPS?

-Andrew

David_Wolinsky@xxxxxxxx wrote:

That's funny, They were sent out formatted nicely...  Tests were run
multiple times for consistency purposes...  Using BEA Jrockit 1.5.

        SPECJBB WebBench                        
        1 Thread        1 Client        2 Clients       4 Clients
8 Clients
        BOPS    TPS     TPS     TPS     TPS
Host    32403.5 213.45  416.86  814.62  1523.78
1 VM    32057           205.4           380.91  569.24  733.8
2 VM    24909.25        NA              399.29  695.1           896.04
4 VM    17815.75        NA              NA              742.78  950.63
8 VM    10216.25        NA              NA              NA
1002.81

        Period  Slice           BOPs
8 VM    1 ms            125 us  6858
8 VM    10 ms           1.25 ms 14287
8 VM    100 ms  12.5 ms 18912
8 VM    1 Sec           .125 Sec        20695
8 VM    2 Sec           .25 Sec 21072
8 VM    10 Sec  1.25 Sec        21797
8 VM    100 Sec 12.5 Sec        11402

Hope it works this time.  If not, I'll submit as an attachment.

David

-----Original Message-----
From: Andrew Theurer [mailto:habanero@xxxxxxxxxx] Sent: Wednesday, August 03, 2005 8:43 PM
To: Wolinsky, David
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-devel] Benchmarking Xen (results and questions)

David_Wolinsky@xxxxxxxx wrote:

Hi all,

Here are some benchmarks that I've done using Xen.

However, before I get started, let me explain some of configuration details...

Xen Version SPECjbb
WebBench
Linux Distribution Debian 3.1
HT disabled
Linux Kernel 2.6.12.2
Host Patch CK3s

Here are the initial benchmarks

SPECJBB WebBench
1 Thread 1 Client 2 Clients 4 Clients 8 Clients BOPS TPS TPS TPS TPS Host 32403.5 213.45 416.86 814.62 1523.78
1 VM 32057 205.4 380.91 569.24 733.8
2 VM 24909.25 NA 399.29 695.1 896.04
4 VM 17815.75 NA NA 742.78 950.63
8 VM 10216.25 NA NA NA 1002.81

(and some more notes.... BOPS - business operations per second, TPS - transactions per second... SPECjbb tests CPU and Memory WebBench (the way we configured it) tests Network I/O and Disk I/O

Values = AVG * VM count
Domain configurations
1 VM - 1660 MB - SPECJBB 1500MB
2 VM - 1280 MB - SPECJBB - 1024MB
4 VM - 640 MB - SPECJBB - 512 MB
8 VM - 320 MB - SPECJBB - 256 MB

Seeing how the SPECjbb numbers declined so bizarrely, I did some scheduling tests and found this out...

Test1: Examine Xen's scheduling to determine if context switching is causing the overhead Period Slice BOPs Modified 8 VM 1 ms 125 us 6858
8 VM 10 ms 1.25 ms 14287
8 VM 100 ms 12.5 ms 18912
8 VM 1 Sec .125 Sec 20695
8 VM 2 Sec .25 Sec 21072
8 VM 10 Sec 1.25 Sec 21797
8 VM 100 Sec 12.5 Sec 11402

Did you run each JBB test config several times to ensure consistent
results? What JVM is this?

Would it be possible to format these more appropriately for email? I am
having a little trouble reading this :)

Thanks,

-Andrew




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