ndt-users list created

["Hao, Justin C" <>]

Howdy Rich,

I've tried with both the command line and the web client, only the web client 
has returned the negative values, but the command line client has also 
returned a wide range of results. what is the recommended java RE to use?

-----
Justin Hao 
CCNA
Network Engineer, ITS Networking
The University of Texas at Austin

-----

On Sep 29, 2010, at 8:30 AM, Rich Carlson wrote:

> Justin;
> 
> The Web100 system uses 32bit counters, so I suspect the negative speeds 
> come from the use of signed int vars instead of unsigned.
> 
> When testing on the local box, the traffic goes through the loopback 
> interface (lo0) instead of the NIC.  This means you are testing the OS 
> and it's memory management system more that anything else. 
> Changing/setting variables on the ethx interface will have no effect.
> 
> You should not set the tcp_mem value to 16 M.  The value for this 
> variable is in pages, NOT bytes.  See 
> Documentation/networking/ip-sysctl.txt doc in the kernel source tree for 
> more details.
> 
> tcp_mem - vector of 3 INTEGERs: min, pressure, max
>         min: below this number of pages TCP is not bothered about its
>         memory appetite.
> 
>         pressure: when amount of memory allocated by TCP exceeds this 
> number
>         of pages, TCP moderates its memory consumption and enters memory
>         pressure mode, which is exited when memory consumption falls
>         under "min".
> 
>         max: number of pages allowed for queueing by all TCP sockets.
> 
>         Defaults are calculated at boot time from amount of available
>         memory.
> 
> 
> Are you using the command line client (web100clt) or the Java Applet 
> (via the browser) to run these tests?  It was recently reported that a 
> site was getting high variability in the S2C tests with the Java client. 
>  It turned out that they had 2 Java consoles installed.  Removing the 
> older console cleared up the problem.
> 
> Regards;
> Rich
> 
> On 9/27/2010 6:49 PM, Hao, Justin C wrote:
>> So i'm setting up a pair of ndt test servers for our new datacenter and 
>> running into some hurdles.
>> 
>> First off, i haven't connected them to each other (or to a 10Gig network), 
>> so all my testing has been on a single box running loopback tests to 
>> itself (i have no other 10GigE hosts available to me at the moment).
>> 
>> I'm running CentOS 5.5 and patched kernel 2.6.35 with the proper web100 
>> version etc.
>> 
>> It's currently hooked up via 1GigE and i've run several different clients 
>> against it and I get good results for 1Gig performance
>> 
>> I'm running loopback tests to tweak TCP settings while I wait for our 
>> 10Gig environment to be made ready. I'm getting 15-18Gig/s for C2S but for 
>> S2C i'm getting numbers all over the place. from 3.5Gig/s to 500Mb/s.  and 
>> most particularly odd, i'm seeing negative numbers in some of the test 
>> output.
>> 
>> I welcome any comments and suggestions for tuning this server (it's a dell 
>> r610 w/ an intel 10GigE adapter)
>> 
>> note: I've also configured the ethernet interface to use 9000 MTU and a 
>> txqueuelen of 10000
>> 
>> Server TCP settings:
>> 
>> # increase TCP max buffer size setable using setsockopt()
>> 
>> net.core.rmem_max = 16777216
>> net.core.wmem_max = 16777216
>> 
>> # increase Linux autotuning TCP buffer limits
>> # min, default, and max number of bytes to use
>> # set max to 16MB for 1GE, and 32M or 54M for 10GE
>> 
>> net.ipv4.tcp_mem = 16777216 16777216 16777216
>> net.ipv4.tcp_rmem = 10240 87380 16777216
>> net.ipv4.tcp_wmem = 10240 65536 16777216
>> 
>> net.ipv4.tcp_window_scaling = 1
>> 
>> # don't cache ssthresh from previous connection
>> net.ipv4.tcp_no_metrics_save = 1
>> 
>> # recommended to increase this for 10G NICS
>> net.core.netdev_max_backlog = 262144
>> 
>> NDT Output:
>> 
>> TCP/Web100 Network Diagnostic Tool v3.6.3
>> Click START to start the test
>> 
>> ** Starting test 1 of 1 **
>> Connecting to '127.0.0.1' [/127.0.0.1] to run test
>> Connected to: 127.0.0.1--  Using IPv4 address
>> Checking for Middleboxes  . . . . . . . . . . . . . . . . . .  Done.
>> Checking for firewalls . . . . . . . . . . . . . . . . . . .  Done.
>> running 10s outbound test (client-to-server [C2S]) . . . . . 13744.22Mb/s
>> running 10s inbound test (server-to-client [S2C]) . . . . . . -83702.57kb/s
>> Server unable to determine bottleneck link type.
>>  [S2C]: Packet queueing detected
>> 
>> Click START to re-test
>> 
>> ** Starting test 1 of 1 **
>> Connecting to '127.0.0.1' [/127.0.0.1] to run test
>> Connected to: 127.0.0.1--  Using IPv4 address
>> Checking for Middleboxes  . . . . . . . . . . . . . . . . . .  Done.
>> Checking for firewalls . . . . . . . . . . . . . . . . . . .  Done.
>> running 10s outbound test (client-to-server [C2S]) . . . . . 12876.05Mb/s
>> running 10s inbound test (server-to-client [S2C]) . . . . . . 1006.86Mb/s
>> Server unable to determine bottleneck link type.
>>  [S2C]: Packet queueing detected
>> 
>> Click START to re-test
>> 
>> ** Starting test 1 of 1 **
>> Connecting to '127.0.0.1' [/127.0.0.1] to run test
>> Connected to: 127.0.0.1--  Using IPv4 address
>> Checking for Middleboxes  . . . . . . . . . . . . . . . . . .  Done.
>> Checking for firewalls . . . . . . . . . . . . . . . . . . .  Done.
>> running 10s outbound test (client-to-server [C2S]) . . . . . 18466.0Mb/s
>> running 10s inbound test (server-to-client [S2C]) . . . . . . 
>> -1710004.63kb/s
>> Server unable to determine bottleneck link type.
>>  [S2C]: Packet queueing detected
>> 
>> Click START to re-test
>> 
>> 
>> -----
>> Justin Hao
>> CCNA
>> Network Engineer, ITS Networking
>> The University of Texas at Austin
>> 
>> -----
>> 
>>