CLOSE_WAIT status

[Marco_67]

Hello,
I'm having problem on a server where is installed an application using the nfsserv process that in certain conditions went into freeze status.
During that time if I check the network connection by using the netstat -na I can see many connection in CLOSE_WAIT status.
The only way to get rid of that status and make the application working again is to restart the nfsserv process. Stating to HP support the server is ok and all necessary patches are installed.
Any clue, suggestion...?
Thank you
Marco

[Fred Ruffet]

What are those conditions ? Does the distant host becomes unreachable ?

Regards,

Fred

[Henk Geurts]

hi Marco
looks like you need the ndd parameter:
tcp_discon
however be carefull with this parameter...

check out other links about this subject:
search for "close_wait" in the forum discussions and you'll find lots of appropriate threads.and fully explained answers.

regards.

[Andrew Cowan]

Is the server very busy, IO timeouts can be caused when there too many inbound comms sessions, or the server is starved of memory. I would start by doing some performance checks on the NFS server.

Next test the latency of the network using ping, traceroute, etc. Try to determine if you are dropping packets and/or experiencing timeouts. If this is the case start looking at switches and routers, and if there are any faulty LAN cables.

[rick jones]

tcp_discon is an extreme kludge and should only be used in extreme circumstances.

CLOSE_WAIT means that the remote has sent this end a FINished segment, and we have ACKed it and sent notification up to the application. TCP is now waiting for the application to call shutdown and/or close.

If CLOSE_WAIT persists for an appreciable length of time, it indicates a bug in the nfsserv application.