ndt-users list created

["Hao, Justin C" <>]

Howdy Rich,

I've got the boxes connected to each other, Server 1 is running ndt 3.6.3 on 
CentOS 5.5 (2.6.35-web100 kernel) and Server 2 is running Perfsonar 3.2rc1 
(looks like ndt 3.4.4a)

I'm still seeing the asynch C2S/S2C values and was wondering if you could 
shed any light/point me in the right direction.   I've included snapshots of 
the web100clt results for each server, please let me know if you need 
additional information. I've configured both servers identically in terms of 
sysctl.conf tcp settings as well as txqueuelen of 10000 and MTU of 9000

Server 1(10.0.0.1) to Server 2(10.0.0.2)
[root@dhcp-135-164
 etc]# web100clt -4 -n 10.0.0.2
Testing network path for configuration and performance problems  --  Using 
IPv4 address
Checking for Middleboxes . . . . . . . . . . . . . . . . . .  Done
checking for firewalls . . . . . . . . . . . . . . . . . . .  Done
running 10s outbound test (client to server) . . . . .  9876.02 Mb/s
running 10s inbound test (server to client) . . . . . . 3041.14 Mb/s
Server unable to determine bottleneck link type.
Information [S2C]: Packet queuing detected: 69.33% (local buffers)
Server '10.0.0.2' is not behind a firewall. [Connection to the ephemeral port 
was successful]
Client is not behind a firewall. [Connection to the ephemeral port was 
successful]
Packet size is preserved End-to-End
Server IP addresses are preserved End-to-End
Client IP addresses are preserved End-to-End
[root@dhcp-135-164
 etc]# 

Server 2(10.0.0.2) to Server 1(10.0.0.1)
[root@localhost
 etc]# web100clt -4 -n 10.0.0.1
Testing network path for configuration and performance problems  --  Using 
IPv4 address
Checking for Middleboxes . . . . . . . . . . . . . . . . . .  Done
checking for firewalls . . . . . . . . . . . . . . . . . . .  Done
running 10s outbound test (client to server) . . . . .  9898.48 Mb/s
running 10s inbound test (server to client) . . . . . . 2622.73 Mb/s
Server unable to determine bottleneck link type.
Information: Other network traffic is congesting the link
Information [S2C]: Packet queuing detected: 72.39% (remote buffers)
Server '10.0.0.1' is not behind a firewall. [Connection to the ephemeral port 
was successful]
Client is not behind a firewall. [Connection to the ephemeral port was 
successful]
Packet size is preserved End-to-End
Server IP addresses are preserved End-to-End
Client IP addresses are preserved End-to-End
[root@localhost
 etc]# 


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

-----

On Sep 29, 2010, at 9:01 AM, Hao, Justin C wrote:

> that was step two, i'm going to connect the two servers to each other and 
> see what i can see
> 
> -----
> Justin Hao
> CCNA
> Network Engineer, ITS Networking
> The University of Texas at Austin
> 
> -----
> 
> On Sep 29, 2010, at 9:00 AM, Rich Carlson wrote:
> 
>> Justin;
>> 
>> Use the latest JRE, but look at the console service.  On Win based
>> machines I've found the upgrade process doesn't remove old version of
>> the java console.  You need to manually do this through the control
>> panel.  I don't have a linux box handy to see what it does.
>> 
>> In any case, I'd say you aren't really testing the NDT tool on a
>> loopback interface, so running the server and client on a single machine
>> isn't really going to tell you much.  Bring up a server and use the
>> applet to test a number of different clients to see what is going on.
>> 
>> Rich
>> 
>> On 9/29/2010 9:37 AM, Hao, Justin C wrote:
>>> 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
>>>>> 
>>>>> -----
>>>>> 
>>>>> 
>>> 
>>> 
>