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Re: Debian GNU/Linux a TCP Workhorse?



Art Lemasters wrote:
>      I would like to find references to examples of Debian GNU/Linux
> systems handling heavy Internet or other network traffic.  Can any of
> you give me any URLs or anecdotes?  How many simultaneous accesses
> have your servers handled?  I would like to present the info to my
> local users' group.  Thanks!
> 
> Art

The others already wrote about Internet servers, I hope my 
experiments qualify as "other network traffic".

We are using Debian systems for IP-over-ATM development here at 
TUT. Yesterday I decided to see how much traffic our boxes would 
push through, so I set up netperf and let if blast for 12 hours.

The experiment was between three machines, one Sun Ultra1 and 
two Debian intel boxes, a PPro 200 and a PII 350. Ultra1 and 
PPro were generating traffic towards PII and PII was generating 
traffic towards PPro. Here's a picture with arrow heads showing 
which way traffic was flowing.

  -------------         --------------        ----------------
 | PPro (urku) | <===> | PII (jaarli) | <--- | Ultra1 (basso) |
  -------------         --------------        ----------------
 
Here are the results from the 12 hour netperf run. The test had 
been running about an hour when a stream from jaarli to urku was 
added. That's why it lasted only 11 hours.

basso% src/netperf-2.1pl3/netperf -l 43200 -H jaarli -- \
                                  -s 131070 -S 131070 -m 1450
TCP STREAM TEST to jaarli
Recv   Send    Send                          
Socket Socket  Message  Elapsed              
Size   Size    Size     Time     Throughput  
bytes  bytes   bytes    secs.    10^6bits/sec  

131070 131070   1450    43202.89     20.20   

urku:~# netperf -l 43200 -H jaarli
TCP STREAM TEST to jaarli
Recv   Send    Send                          
Socket Socket  Message  Elapsed              
Size   Size    Size     Time     Throughput  
bytes  bytes   bytes    secs.    10^6bits/sec  

 65535  65535  65535    43208.72     31.72   

jaarli:~# netperf -l39600 -H urku
TCP STREAM TEST to urku
Recv   Send    Send                          
Socket Socket  Message  Elapsed              
Size   Size    Size     Time     Throughput  
bytes  bytes   bytes    secs.    10^6bits/sec  

 65535  65535  65535    39599.84     88.87   


Ifconfig from jaarli shows this:
lec0   Link encap:Ethernet  HWaddr 00:20:48:0E:67:B7  
       inet addr:10.10.54.208  Bcast:10.10.54.255  Mask:255.255.255.192
       UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
       RX packets:486241122 errors:0 dropped:0 overruns:0 frame:0
       TX packets:492656611 errors:0 dropped:103 overruns:0 carrier:0
       Collisions:0 

cat /proc/interrupts shows this:
jaarli:~# cat /proc/interrupts 
           CPU0       
  0:    8280457          XT-PIC  timer
  1:      22535          XT-PIC  keyboard
  2:          0          XT-PIC  cascade
  5:      17410          XT-PIC  soundblaster
  9:     299899          XT-PIC  eth0
 10:  912585790          XT-PIC  nicstar
 13:          1          XT-PIC  fpu
 14:      73753          XT-PIC  ide0
 15:      19369          XT-PIC  ide1
NMI:          0

The uptime of the box is a little over day and currently the 
interrupt count from nicstar (Fore LE155 ATM card actually) is 
well over one billion.

If I calculated correctly, the traffic handled by jaarli was 
over 670Gbytes during the test (add everything together, divide 
by 8 and then divide by 1024^3 to gigabytes).

The test is a little silly, since it only measures raw TCP 
throughput and nothing else, but maybe it usable for 
presentations :)

// Heikki
-- 
Heikki Vatiainen                  * hessu@cs.tut.fi
Tampere University of Technology  * Tampere, Finland



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