ndd and recommended tcp parameters for use as web server

[Barry O Flanagan]

Hi folks,

Anyone got any recommended parameter settings/tunings for /etc/rc.config.d/nddconf for a machine that will be used as a high volume web server?

Specifically, anything in relation to dropping any inactive TCP connections quickly?

Any white paper links would be great!

TIA,
Barry

[Rajeev Tyagi]

Barry,


I can recommned few parameters which are very important for your webserver.

tcp_time_wait_interval
ndd/dev/tcp
60000
60000

tcp_conn_req_max
ndd/dev/tcp
20
4096

tcp_ip_abort_interval
ndd/dev/tcp
600000
60000

tcp_keepalive_interval
ndd/dev/tcp
72000000
900000

tcp_rexmit_interval_initial
ndd/dev/tcp
1500
1500

tcp_rexmit_interval_max
ndd/dev/tcp
60000
60000

tcp_rexmit_interval_min
ndd/dev/tcp
500
500

tcp_xmit_hiwater_def
ndd/dev/tcp
32768
32768

tcp_recv_hiwater_def
ndd/dev/tcp
32768
32768

Rajeev

[Brian Hackley]

Barry,

I'd also set the fin_wait_2 timer (requires PHNE_19375 or better of the ARPA Transport patch). tcp_fin_wait_2_timeout is set in milliseconds. 0 means no timeout (keep forever).

Check the current value:

ndd -get /dev/tcp tcp_fin_wait_2_timeout
Set the FIN_WAIT2 timeout to 10 minutes:

ndd -set /dev/tcp tcp_fin_wait_2_timeout 600000

Hope this helps,

-> Brian Hackley