[httperf] Connection Resets - need some description

Deepak Hegde httperf@napali.hpl.hp.com
Wed, 12 Sep 2001 08:24:50 -0700 (PDT)


In the tests that I run using httperf, I get the
connection resets. Can some one help me understand the
meaning of connection resets in the context of
HTTP/httperf ?. The (load generating) client & web
server are running under Linux on high-end machines
connected by GBits/sec network. httperf generates the
HTTP requests to an EJB application which takes more
time to run and return results (than a simple HTTP

Both the web server and the application server (IBM
WebSphere) are configured to support large number of

I guess something in the pipe ay be limiting the
connection queue lengths and thereby resulting in
closure of TCP connections. The SYN cookies and SYN
backlogs are enabled to allow queing of TCP connection

Which Apache/WebSphere/OS parameters should be tuned
to avoid connection resets during httperf tests ?

Any thoughts ?

httperf --hog --client=0/1 --server=linux01 --port=80
--rate=100 --send-buffer=4096 --recv-buffer=16384
--num-conns=1000 --num-calls=1
Maximum connect burst length: 1

Total: connections 1000 requests 1000 replies 591
test-duration 25.258 s

Connection rate: 39.6 conn/s (25.3 ms/conn, <=767
concurrent connections)
Connection time [ms]: min 735.9 avg 8451.9 max 23538.7
median 5910.5 stddev 6126.9
Connection time [ms]: connect 4.7
Connection length [replies/conn]: 1.000

Request rate: 39.6 req/s (25.3 ms/req)
Request size [B]: 93.0

Reply rate [replies/s]: min 11.2 avg 22.4 max 36.0
stddev 11.4 (5 samples)
Reply time [ms]: response 7720.1 transfer 725.7
Reply size [B]: header 332.0 content 15071.0 footer
2.0 (total 15405.0)
Reply status: 1xx=0 2xx=591 3xx=0 4xx=0 5xx=0

CPU time [s]: user 0.37 system 24.76 (user 1.5% system
98.0% total 99.5%)
Net I/O: 355.6 KB/s (2.9*10^6 bps)

Errors: total 409 client-timo 0 socket-timo 0
connrefused 0 connreset 409
Errors: fd-unavail 0 addrunavail 0 ftab-full 0 other 0

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