How to release sockets

[sid_22]

Hi

We have a parameter system which lasts more than 15 minute so that the system releases the socket after 15 minutes (for Aix the parameter is closed wait), it is a parameter of the core of HPUX system. We want to reduce this default value to have a maximum of 2 or 4 seconds .

Please help you have a solution for this problem

Thanks

[Steve Steel]

Hi


Should be ndd

see man ndd

The parameter tcp_keepalive_interval determines the amount of time that TCP waits for an idle connection with no unacknowledged data before sending keepalive packets.


Steve Steel

[Senthil Kumar .A_1]

Hi,

Try ..

ndd â  set /dev/tcp tcp_fin_wait_2_timeout 60000

To make the change permanent:
Modify /etc/rc.config.d/ndd.conf by adding the following line:
TRANSPORT_NAME[0]=tcp
NDD_NAME[0]=tcp_fin_wait_2_timeout
NDD_VALUE[0]=60000

make sure .. the 0 in [0] is repalced by the last number that follows the existing sequence.

60000 millisec = 1 minute.

regards,
Senthil Kumar .A

[Tiziano Contorno _]

If you see hanging CLOSE_WAIT sockets it means the client didn't send the proper last ack. You have to manually kill them with ndd if you are running low on sockets.

I do not remember any tunable parameter for CLOSE_WAIT, I had to write a ndd script to kill sockets in CLOSE_WAIT...

Attached a simple TCP connection diagram.

[Senthil Kumar .A_1]

Hi in my previous reponse,

please replace use tcp_time_wait_interval instead of tcp tcp_fin_wait_2_timeout ,


so the actual procedure should be..

ndd -set /dev/tcp tcp_time_wait_interval 60000

To make the change permanent:
Modify /etc/rc.config.d/ndd.conf by adding the following line:
TRANSPORT_NAME[0]=tcp
NDD_NAME[0]=tcp_time_wait_interval
NDD_VALUE[0]=60000

make sure .. the 0 in [0] is repalced by the last number that follows the existing sequence.

60000 millisec = 1 minute.

regards,
Senthil Kumar .A

[sid_22]

Thanks you all for your response. We will try

[rick jones]

tcp_time_wait_interval will only control how long a connection remains in TIME_WAIT

tcp_keepalive_interval is how long before keepalives start on an established connection, it will wait tcp_ip_abort_interval for a reply to the keepalive probes.

tcp_keepalive_detached_interval is how long before keepalives start on a connection on which the user has called close() - this is to cull FIN_WAIT_2 connections without IIRC having to resort to the kludge of the fin_wait_2 timeout

if the problem is connections in TIME_WAIT, the solution is NOT to reduce TIME_WAIT but to increase the number of ports being used

please try to be a bit more specific about what you want to do

ftp://ftp.cup.hp.com/dist/networking/briefs/annotated_ndd.txt