HTTrack Website Copier
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Subject: Re: CLOSE_WAIT problems
Author: Xavier Roche
Date: 01/29/2003 08:58
> I have been using HTTrack alongside an Apache Tomcat4 web-
> server to generate the static portions of my web-site 
> great success - fantastic product!). I have found however 
> that under moderate load occasionally the web-server 
> process will stall (and stop serving) due to a number of 
> TCP connections  entering the CLOSE_WAIT state.  The only 
> way to release these is by restarting the web-server.  I 
> a little confused as to which application might be 
> this issue (Tomcat or HTTrack).  I have a feeling it 
> be HTTrack occasionally failing to call the final close
> however I might be wrong.

According to various network folks,

"CLOSE_WAIT is the state a TCP connection enters when the 
remote half has sent a FIN and now the local TCP is waiting 
for the local application to call close().  There is no 
timer running for the CLOSE_WAIT state - it will stay there 
until the app calls close() (perhaps shutdown) or the app 

I will recheck the way httrack handles closes, but I doubt 
this is a missing close problem (httrack would crash very 
quickly, as more that 64 sockets can not be opened 
simultaneously). I could also issue a shutdown() before the 
close(), but this tend to cause problems on some buggy 

httrack: FIN -> :server
(httrack called close())

httrack: ACK <- :server
(the server kernel detected the close)

--> here the server is in CLOSE_WAIT state

httrack: FIN <- :server
(the server application called () close and confirmed by 
sending a FIN)

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All articles

Subject Author Date
CLOSE_WAIT problems

01/29/2003 00:06
Re: CLOSE_WAIT problems

01/29/2003 08:58
Re: CLOSE_WAIT problems - BUG confirmed!

01/29/2003 19:08
Re: CLOSE_WAIT problems - BUG confirmed!

01/29/2003 22:00


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