[httperf] Can httperf generate session whose length isexponentiallydistributed?

Martin Arlitt arlitt@granite.hpl.hp.com
Wed, 12 Mar 2003 09:08:51 -0800 (PST)


Weiyaya

the httperf output indicates that 1,278 connections were reset by the
server (i.e., the server sent a TCP RST packet to the client).  Since you
are using persistent connections, I expect that these error occur when the
client attempts to issue another request on a connection that the server
has just closed.  under normal circumstances the client would not do this,
but your server seems to be overloaded, so perhaps the client is issuing
the request before it has seen the server close the connection.  if you
use tcpdump to monitor the network traffic you should be able to identify
what is going on (by analyzing the individual TCP connections that are
being reset).

Martin


On Wed, 12 Mar 2003, yywei wrote:

> Dear Martin,
>    I got an output as follows. The connreset error is 1278. Why such error occurs?  In my apapche server,
> The "SOMAXCONN" is 128 default.
> 
>     
> [wyy@dmb httperf-0.8]$ httperf --hog --port 80 --rate 1 --failure-status 503  --server 166.111.70.100 --timeout 5 --uri /cgi-bin/test.pl --wsess 600,8,8   --session-cookies  --client 0/2
> httperf --hog --timeout=5 --client=0/2 --server=166.111.70.100 --port=80 --uri=/cgi-bin/test.pl --failure-status=503 --rate=1 --send-buffer=4096 --recv-buffer=16384 --session-cookies --wsess=600,8,8.000
> Maximum connect burst length: 3
> 
> Total: connections 1878 requests 3156 replies 1321 test-duration 666.613 s
> 
> Connection rate: 2.8 conn/s (355.0 ms/conn, <=42 concurrent connections)
> Connection time [ms]: min 192.9 avg 9991.8 max 13037.7 median 10189.5 stddev 2102.7
> Connection time [ms]: connect 0.5
> Connection length [replies/conn]: 1.000
> 
> Request rate: 4.7 req/s (211.2 ms/req)
> Request size [B]: 112.0
> 
> Reply rate [replies/s]: min 0.0 avg 2.0 max 5.2 stddev 1.2 (133 samples)
> Reply time [ms]: response 2250.0 transfer 0.0
> Reply size [B]: header 197.0 content 584.0 footer 2.0 (total 783.0)
> Reply status: 1xx=0 2xx=0 3xx=0 4xx=0 5xx=1321
> 
> CPU time [s]: user 152.73 system 504.31 (user 22.9% system 75.7% total 98.6%)
> Net I/O: 2.0 KB/s (0.0*10^6 bps)
> 
> Errors: total 1835 client-timo 557 socket-timo 0 connrefused 0 connreset 1278
> Errors: fd-unavail 0 addrunavail 0 ftab-full 0 other 0
> 
> Session rate [sess/s]: min 0.00 avg 0.06 max 1.00 stddev 0.13 (43/600)
> Session: avg 8.00 connections/session
> Session lifetime [s]: 74.4
> Session failtime [s]: 23.0
> Session length histogram: 134 156 123 64 35 31 10 4 43
> 
>   Thank you for your help!!!!!!
> 
> Sincerely,
> 
> Weiyaya
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