Discussion list for thrulay, a network testing tool

["Cottrell, Les" <>]

We ran pings while running the thrulay. The pings were pretty steady at about 
72ms, even when we ran the pings at 0.2 sec intervals. Connie can you run a 
longer test to see if the RTTs stabilize. Dantong or Jason, are there any 
other machines we can test to at BNL to see if we can isolate the problem?  
Connie if you make measurements with thrulay from atlasprod3 then we can see 
if all paths from atlasprod3 have similar RTTs.  

-----Original Message-----
From: stanislav shalunov 
[mailto:]
 
Sent: Monday, March 28, 2005 5:18 PM
To: Logg, Connie A.
Cc: Cottrell, Les; Dantong Yu; 

Subject: Re: 3 site comparison

Connie,

Somewhere along the line there's a huge buffer that's filled up.
Might be honest-to-goodness network congestion (buffers of several seconds 
are more common than one would hope), or it might be a measurement artifact 
(an internal queue inside the measurement machine).

What delay do you observe with ping and/or owping to the BNL site when 
throughput tests are not running?

Given that the delay values measured with thrulay seem to be increasing (Is 
it possible to run a longer test?  At least the default 60 seconds?), chances 
are the buffer is internal to the client host (the one from which thrulay, 
rather than thrulayd, is run); if that's right, then there could be some 
non-congestive loss on the path.

                                                        --Stas

"Logg, Connie A." 
<>
 writes:

> I am trying to use thrulay to diagnose (find) low bandwidth problems.  
> Below I run it to 3 nodes, One at caltech, one at cern, and one at 
> bnl.  We are assuming the bnl node is 1 gig also.  Note that bnl gives 
> very low throughput and very high rtt. It is much must worse than 
> cern.
> 
> Does anyone have any ideas why this might be?  All of our tests are 
> show low bandwidth to bnl.
> 
> Connie
> 
> Connie Logg - Network Analyst
> Stanford Linear Accelerator Center
> 2575 Sand Hill Road, Menlo Park, CA 94025 650-926-2879, 
> 
>  "If is the middle word in life, but happiness is 
> found along the way, not at the end of the road."
> 
> 
> > ______________________________________________ 
> > From:       Logg, Connie A.  
> > Sent:       Monday, March 28, 2005 4:09 PM
> > To: Cottrell, Les
> > Subject:    3 site comparison
> > 
> > 
> > 540cal@nettest2:
> >  thrulay -t 15 socrates.cacr.caltech.edu # local 
> > window = 8388608B; remote window = 8388608B # block size = 8192B # 
> > test duration = 15s; reporting interval = 1s
> > # begin, s  end, s  Mb/s    RTT, ms: min  avg      max
> >     0.000    1.013  127.970   60.774  347.234  544.039
> >     1.013    2.005  165.705  281.654  304.308  322.964
> >     2.005    3.010  174.784  270.473  287.119  305.195
> >     3.010    4.005  182.550  251.698  274.526  297.148
> >     4.005    5.002  189.492  241.689  264.378  280.380
> >     5.002    6.016  195.973  243.144  255.918  271.018
> >     6.016    7.000  201.608  231.258  248.784  271.616
> >     7.000    8.016  207.058  219.784  242.043  262.371
> >     8.016    9.001  378.999   86.427  143.653  248.692
> >     9.001   10.007  612.159   70.501   82.888   95.179
> >    10.007   11.003  677.555   68.272   74.853   86.818
> >    11.003   12.006  730.937   60.483   68.686   77.425
> >    12.006   13.004  769.255   54.579   65.030   81.205
> >    13.004   14.001  812.013   52.381   61.406   74.485
> >    14.001   15.003  494.601   55.863   99.081  118.561
> > #   0.000   15.003  394.431   52.381  126.856  544.039
> > 
> > 
> > 541cal@nettest2:
> >  thrulay -t 15 pcgiga.cern.ch # local window = 
> > 8388608B; remote window = 8388608B # block size = 8192B # test 
> > duration = 15s; reporting interval = 1s
> > # begin, s  end, s  Mb/s    RTT, ms: min  avg      max
> >     0.000    1.037    1.074  505.381 1186.711 1542.244
> >     1.037    2.032   22.797 1542.269 2178.259 2530.916
> >     2.032    3.006  154.542  199.308  765.646 2707.753
> >     3.006    4.017  234.742  166.105  216.948  361.916
> >     4.017    5.006  251.841  166.160  193.848  243.294
> >     5.006    6.116  156.582  168.959  212.099  594.177
> >     6.116    7.007   65.257  593.313  885.178 1215.424
> >     7.007    8.012  141.368  266.727  388.116  724.935
> >     8.012    9.041  142.460  244.362  327.710  409.416
> >     9.041   10.011  152.071  261.289  319.297  382.199
> >    10.011   11.007  147.746  261.606  317.665  403.618
> >    11.007   12.011  146.701  252.688  326.833  397.908
> >    12.011   13.006  142.232  284.193  328.283  401.246
> >    13.006   14.004  146.668  273.632  332.103  404.795
> >    14.004   15.034  150.079  290.990  327.100  385.978
> > #   0.000   15.034  137.403  166.105  360.599 2707.753
> > 
> > 
> > 542cal@nettest2:
> >  thrulay -t 15 atlasprod3.usatlas.bnl.gov # local 
> > window = 8388608B; remote window = 8388608B # block size = 8192B # 
> > test duration = 15s; reporting interval = 1s
> > # begin, s  end, s  Mb/s    RTT, ms: min  avg      max
> >     0.000    1.057   15.753  177.788  937.399 1230.636
> >     1.057    2.000   11.459 1230.387 1577.201 2172.282
> >     2.000    3.007    9.897 2172.265 2651.757 3176.500
> >     3.007    4.020   10.609 3176.260 3657.310 4186.513
> >     4.020    5.026   11.397 3770.564 3970.239 4260.845
> >     5.026    6.031   12.261 4113.077 4463.307 4758.109
> >     6.031    7.049    6.502 4467.244 4610.031 4906.013
> >     7.049    8.068    4.308 4906.036 5220.364 5493.553
> >     8.068    9.006    5.171 5493.571 5721.198 5927.811
> >     9.006   10.021    6.072 5927.873 6157.883 6363.394
> >    10.021   11.033    6.997 6362.849 6550.688 6723.245
> >    11.033   12.047    7.816 6723.205 6893.487 7092.054
> >    12.047   13.064    8.638 7020.672 7205.746 7390.961
> >    13.064   14.002    9.574 7315.839 7440.941 7536.118
> >    14.002   15.008    6.771 6723.759 6933.584 7388.117
> > #   0.000   15.008    8.899  177.788 4465.330 7536.118
> > 5
> > 
> > Connie Logg - Network Analyst
> > Stanford Linear Accelerator Center
> > 2575 Sand Hill Road, Menlo Park, CA 94025 650-926-2879, 
> > 
> >  "If is the middle word in life, but happiness 
> > is found along the way, not at the end of the road."
> > 

-- 
Stanislav Shalunov              http://www.internet2.edu/~shalunov/

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