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From Vy Ho <st946...@drexel.edu>
Subject Re: RE : Server refuse connection with many TIME_WAIT
Date Wed, 15 Dec 2004 16:05:53 GMT
Great! Thank you very much for the insight information.  I haven't tried 
this yet, but it appears to be right on the bull eyes.

Thanks again,

Vy Ho

LERBSCHER Jean-Pierre wrote:

>TIME_WAIT means "client enters this state after active close".
>It's normal to have a socket in this state for a period of time. This time
>is specified by the rfc 793 as twice the MSL (Maximum Segment Lifetime).
>Some systems implement different values but the specification is 2 mn.
>
>I read this comment from internet... I think it could help you!
>
>Setting the TCP TIME_WAIT time
>When you expect to serve many TCP/IP connections, it is important to check
>the time your Server OS waits before releasing a logically closed TCP/IP
>socket. If this time is too long, those "died" sockets can consume all OS
>TCP/IP resources, and all new connections will be rejected on the OS level,
>so the CommuniGate Pro Server will not be able to warn you. 
>This problem can be seen even on the sites that have just few hundred
>accounts. This indicates that some of the clients have configured their
>mailers to check the server too often. If client mailers connect to the
>server every minute, and the OS TIME_WAIT time is set to 2 minutes, the
>number of "died" sockets will grow, and eventually, they will consume all OS
>TCP/IP resources. 
>
>It is recommended to set the TIME_WAIT time to 20-30 seconds. 
>
>The TIME_WAIT problem is a very common one for Windows NT systems. Unlike
>most Unix systems, Windows NT does not have a generic setting for the
>TIME_WAIT interval modification. To modify this setting, you should create
>an entry in the Windows NT Registry (the information below is taken from the
>http://www.microsoft.com site:
>
>Run Registry Editor (RegEdit.exe). 
>Go to the following key in the registry: 
>HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\tcpip\Parameters 
>Choose Add Value from the Edit menu and create the following entry:
>Value Name: 
>TcpTimedWaitDelay 
>Data Type: 
>REG_DWORD 
>Value: 
>30-300 (decimal) - time in seconds 
>Default: 0xF0 (240 decimal) not in registry by default 
>Quit the Registry Editor 
>Restart the computer for the registry change to take effect. 
>Description: This parameter determines the length of time that a connection
>will stay in the TIME_WAIT state when being closed. While a connection is in
>the TIME_WAIT state, the socket pair cannot be reused. This is also known as
>the "2MSL" state, as by RFC the value should be twice the maximum segment
>lifetime on the network. See RFC793 for further details. 
>
>
>-----Message d'origine-----
>De : V D [mailto:st946tbf@drexel.edu] 
>Envoyé : mercredi 15 décembre 2004 05:17
>À : tomcat-user@jakarta.apache.org
>Objet : Server refuse connection with many TIME_WAIT
>
>
>I have an Axis service that runs under Tomcat 5.5.4.  I use gSoap client 
>to connect to the server.  After about 3960 requests from the clients, 
>the Tomcat stops accepting connection.  I have to wait for serveral 
>minutes for it to accept connections again.
>
>This is under MS Windows XP system.  Using the command line:
>
>netstat -a<enter>
>
>I have about 5000 TIMEWAIT:
>
>TCP    vd:5000                localhost:http         TIME_WAIT
>
>Looking through TcpMonitor, both the client and server send in close 
>message:
>
>CLIENT MESSAGE:
>
>POST /axis/services/TestService HTTP/1.1
>Host: 127.0.0.1:82
>User-Agent: gSOAP/2.7
>Content-Type: text/xml; charset=utf-8
>Content-Length: 552
>Connection: close
>SOAPAction: ""
>
>....
>
>SERVER MESSAGE:
>
>HTTP/1.1 200 OK
>Server: Apache-Coyote/1.1
>Content-Type: text/xml;charset=utf-8
>Date: Wed, 15 Dec 2004 04:04:52 GMT
>Connection: close
>
>What's going on?  Is there any flag I can set in Tomcat to close these 
>TIMEWAIT connections?
>
>Looking at the clients's memory foot print, the memory does not go up at 
>all after all these connections.
>The strange thing is this:  using Java's client to repeatedly request 
>the server for many thousand times, and I don't have any problem with 
>the server.  Using the command line "netstat -a", and I still see many 
>TIMEWAIT.
>
>Could this have something to do with gSoap, not Tomcat?
>
>Thanks,
>
>V D
>
>
>
>
>
>
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>  
>


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