cvs commit: apachen/htdocs/manual/misc fin_wait_2.html

[Marc Slemko <ma...@hyperreal.org>]

marc        97/09/06 20:10:59

  Modified:    htdocs/manual/misc fin_wait_2.html
  Log:
  Update the fin_wait_2 page to reflect the current understanding
  of the issues; remove the suggestion that Apache is buggy, since
  no bugs have been found in that code.  It now appears most likely
  that it is just the result of a bad interaction.  The real solution,
  as always, is still a timeout for FIN_WAIT_2.
  
  Revision  Changes    Path
  1.12      +12 -13    apachen/htdocs/manual/misc/fin_wait_2.html
  
  Index: fin_wait_2.html
  ===================================================================
  RCS file: /export/home/cvs/apachen/htdocs/manual/misc/fin_wait_2.html,v
  retrieving revision 1.11
  retrieving revision 1.12
  diff -u -r1.11 -r1.12
  --- fin_wait_2.html	1997/08/17 05:55:54	1.11
  +++ fin_wait_2.html	1997/09/07 03:10:58	1.12
  @@ -43,8 +43,8 @@
   
   <LI><H2>But why does it happen?</H2>
   
  -There are several reasons for it happening, and not all of them are
  -fully understood by the Apache team yet.  What is known follows.<P>
  +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>
   
  @@ -111,15 +111,14 @@
   all servers that support persistent connections, including Apache 1.1.x
   and 1.2.<P>
   
  -<H3>Something in Apache may be broken</H3>
  +<H3>A necessary bit of code introduced in 1.2</H3>
   
   While the above bug is a problem, it is not the whole problem.
   Some users have observed no FIN_WAIT_2 problems with Apache 1.1.x,
   but with 1.2b enough connections build up in the FIN_WAIT_2 state to
  -crash their server.  We have not yet identified why this would occur
  -and welcome additional test input.<P>
  +crash their server.  
   
  -One possible (and most likely) source for additional FIN_WAIT_2 states
  +The most likely source for additional FIN_WAIT_2 states
   is a function called <CODE>lingering_close()</CODE> which was added
   between 1.1 and 1.2.  This function is necessary for the proper
   handling of persistent connections and any request which includes
  @@ -134,13 +133,13 @@
   the connection has closed.
   See the <A HREF="#appendix">appendix</A> for more details.<P>
   
  -We have not yet tracked down the exact reason why
  -<CODE>lingering_close()</CODE> causes problems.  Its code has been
  -thoroughly reviewed and extensively updated in 1.2b6.  It is possible
  -that there is some problem in the BSD TCP stack which is causing the
  -observed problems.  It is also possible that we fixed it in 1.2b6.
  -Unfortunately, we have not been able to replicate the problem on our
  -test servers.<P>
  +The code in <CODE>lingering_close()</CODE> appears to cause problems
  +for a number of factors, including the change in traffic patterns
  +that it causes.  The code has been thoroughly reviewed and we are
  +not aware of any bugs in it.  It is possible that there is some
  +problem in the BSD TCP stack, aside from the lack of a timeout
  +for the FIN_WAIT_2 state, exposed by the <CODE>lingering_close</CODE>
  +code that causes the observed problems.<P>
   
   <H2><LI>What can I do about it?</H2>