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  1. Jan 27, 1998
  3. Jan 26, 1998
    • dgaudet's avatar
      API additions: table_setn, table_addn, table_mergen... for speed! · 99f9ce84
      dgaudet authored 
      POOL_DEBUG support for correctness.

Submitted by:	Dmitry Khrustalev <dima@bog.msu.su>, Dean Gaudet
Reviewed by:	Brian Behlendorf, Jim Jagielski


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@80025 13f79535-47bb-0310-9956-ffa450edef68
      99f9ce84
    • lookit's avatar
      Server-generated pages can be server-signed now (new directive) · e6918e46
      lookit authored 
      
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@80024 13f79535-47bb-0310-9956-ffa450edef68
      e6918e46
    • Ken Coar's avatar
      A truly mighty mod normalising HTML tags to uppercase, and · 64ca8f8b
      Ken Coar authored 
      	'i' and 'b' to 'EM' and 'STRONG' respectively.  Been threatening
	to do this for months.. no-one need try to maintain this when
	writing/modifiying the docs.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@80022 13f79535-47bb-0310-9956-ffa450edef68
      64ca8f8b
    • lookit's avatar
      Fix CGI-Execution for EBCDIC hosts. · 27d89ed4
      lookit authored 
      
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@80020 13f79535-47bb-0310-9956-ffa450edef68
      27d89ed4
    • brian's avatar
      PR: · 9c1665e0
      brian authored 
      tsk tsk, randy.  Can't find this on covalent.net either.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@80016 13f79535-47bb-0310-9956-ffa450edef68
      9c1665e0
    • brian's avatar
      PR: · 7b268e6f
      brian authored 
      David Robinson's CGI specification is no longer available at this URL.  perhaps
we should point at other CGI resources online?


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      7b268e6f
    • brian's avatar
      PR: · 236446c6
      brian authored 
      If SGI is going to break their links, I'm not about to go ferreting around
their site looking for where they moved it to.  Since the other entry is
generic for all OS's (or at least doesn't clearly state HOW it's related),
I've removed the SGI entry.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@80012 13f79535-47bb-0310-9956-ffa450edef68
      236446c6
    • brian's avatar
      PR: · 083f8444
      brian authored 
      If SCO's going to break their links, I'm not going to go searching for where they
moved it to.

Cold and rainy and dark.
ml" -->

<H1 ALIGN="CENTER">Connections in the FIN_WAIT_2 state and Apache</H1>
<OL>
<LI><H2>What is the FIN_WAIT_2 state?</H2>
Starting with the Apache 1.2 betas, people are reporting many more
connections in the FIN_WAIT_2 state (as reported by
<code>netstat</code>) than they saw using older versions.  When the
server closes a TCP connection, it sends a packet with the FIN bit
sent to the client, which then responds with a packet with the ACK bit
set.  The client then sends a packet with the FIN bit set to the
server, which responds with an ACK and the connection is closed.  The
state that the connection is in during the period between when the
server gets the ACK from the client and the server gets the FIN from
the client is known as FIN_WAIT_2.  See the <A
HREF="ftp://ds.internic.net/rfc/rfc793.txt">TCP RFC</A> for the
technical details of the state transitions.<P>

The FIN_WAIT_2 state is somewhat unusual in that there is no timeout
defined in the standard for it.  This means that on many operating
systems, a connection in the FIN_WAIT_2 state will stay around until
the system is rebooted.  If the system does not have a timeout and
too many FIN_WAIT_2 connections build up, it can fill up the space
allocated for storing information about the connections and crash
the kernel.  The connections in FIN_WAIT_2 do not tie up an httpd
process.<P>

<LI><H2>But why does it happen?</H2>

There are numerous reasons for it happening, some of them may not
yet be fully clear.  What is known follows.<P>

<H3>Buggy clients and persistent connections</H3>

Several clients have a bug which pops up when dealing with
<A HREF="../keepalive.html">persistent connections</A> (aka keepalives).
When the connection is idle and the server closes the connection
(based on the <A HREF="../mod/core.html#keepalivetimeout">
KeepAliveTimeout</A>), the client is programmed so that the client does
not send back a FIN and ACK to the server.  This means that the
connection stays in the FIN_WAIT_2 state until one of the following
happens:<P>
<UL>
        <LI>The client opens a new connection to the same or a different
            site, which causes it to fully close the older connection on
            that socket.
        <LI>The user exits the client, which on some (most?) clients
            causes the OS to fully shutdown the connection.
        <LI>The FIN_WAIT_2 times out, on servers that have a timeout
            for this state.
</UL><P>
If you are lucky, this means that the buggy client will fully close the
connection and release the resources on your server.  However, there
are some cases where the socket is never fully closed, such as a dialup
client disconnecting from their provider before closing the client.
In addition, a client might sit idle for days without making another
connection, and thus may hold its end of the socket open for days
even though it has no further use for it.
<STRONG>This is a bug in the browser or in its operating system's
TCP implementation.</STRONG>  <P>

The clients on which this problem has been verified to exist:<P>
<UL>
        <LI>Mozilla/3.01 (X11; I; FreeBSD 2.1.5-RELEASE i386)
        <LI>Mozilla/2.02 (X11; I; FreeBSD 2.1.5-RELEASE i386)
        <LI>Mozilla/3.01Gold (X11; I; SunOS 5.5 sun4m)
        <LI>MSIE 3.01 on the Macintosh
        <LI>MSIE 3.01 on Windows 95
</UL><P>

This does not appear to be a problem on:
<UL>
        <LI>Mozilla/3.01 (Win95; I)
</UL>
<P>

It is expected that many other clients have the same problem. What a
client <STRONG>should do</STRONG> is periodically check its open
socket(s) to see if they have been closed by the server, and close their
side of the connection if the server has closed.  This check need /export/home/cvs/CVSROOT/cvsedit


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    • brian's avatar
      PR: · 81467561
      brian authored 
      Make all references complete.


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      81467561
    • brian's avatar
      PR: · fba81e20
      brian authored 
      
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@80005 13f79535-47bb-0310-9956-ffa450edef68
      fba81e20
  5. Jan 25, 1998
  7. Jan 24, 1998