what does "close wait" and "fin_wait2" means?

[hanhao]

1. what does "close wait" means?
2. what does "fin_wait2" means?

i understand that these are socket status but
- what do they mean? the socket is waiting for server? the socket is shutting down but waiting for certain event to happen before it's allowed to shutdown?
- what situations causes them?
- it seems that the socket is waiting for something, how can i stop the close wait/fin_wait2 and shutdown the socket? (gracefully or forcefully)

it seems that sockets on "close wait" and "fin_wait2" on my program are the ones with problems

please advise

[Danny]

A quick search on Google reveals the following"

"FIN_WAIT2 is a state when the server closes the socket on its side but
does not receive an acknowledgement of the close from the client. Does
your application open and close a lot of connections? When you close on
the client side do you use the Connection.close() method? "

CLOSE_WAIT also seems fishy: http://www.nowsms.com/framer.htm?htt.../485/4021.html
In short, yes, these statuses indicate bugs either on your side or a the socket libraries you're using. And yes, they have an adverse impact on performance.

[hanhao]

A quick search on Google reveals the following"

"FIN_WAIT2 is a state when the server closes the socket on its side but
does not receive an acknowledgement of the close from the client. Does
your application open and close a lot of connections? When you close on
the client side do you use the Connection.close() method? "

CLOSE_WAIT also seems fishy: http://www.nowsms.com/framer.htm?htt.../485/4021.html
In short, yes, these statuses indicate bugs either on your side or a the socket libraries you're using. And yes, they have an adverse impact on performance.

thanks for your reply

yes, u guessed correct. my application open and close many many connections in a short time (about 20)

i dont use Connection.close() , but i use the closesocket() api. closesocket() should work right?

	closesocket(theSocket);
	WSACleanup();

	return 0;
}