From nobody@hyperreal.org Thu Jul 17 12:00:28 1997 Received: (from nobody@localhost) by hyperreal.org (8.8.5/8.8.5) id MAA08748; Thu, 17 Jul 1997 12:00:28 -0700 (PDT) Message-Id: <199707171900.MAA08748@hyperreal.org> Date: Thu, 17 Jul 1997 12:00:28 -0700 (PDT) From: Clinton Work Reply-To: work@cadvision.com To: apbugs@hyperreal.org Subject: Server stops responding when a socket gets stuck in the CLOSE_WAIT state X-Send-Pr-Version: 3.2 >Number: 878 >Category: os-aix >Synopsis: Server stops responding when a socket gets stuck in the CLOSE_WAIT state >Confidential: no >Severity: serious >Priority: medium >Responsible: apache >State: closed >Class: sw-bug >Submitter-Id: apache >Arrival-Date: Thu Jul 17 12:10:01 1997 >Last-Modified: Sun Jul 19 00:52:15 PDT 1998 >Originator: work@cadvision.com >Organization: >Release: 1.2.1 >Environment: AIX Version 4.1.5 compiled with gcc 2.7.2 (-O2) uname -a: AIX elmo 1 4 00052856A000 >Description: When the default USE_LINGER option is compiled in the apache server will occasionlly lock up and stop accepting new requests. If you do a netstat -na you will see that one of the client sockets is in the CLOSE_WAIT state. It does not timeout after 30 seconds, and the server stays locked up until its send the server a -HUP or -USR1 signal. I got the Server to lockup by constantly reloading a page with lots of graphics on both MSIE 3.01 on Windows 95 and Netscape 3.01 on an RS6000 AIX workstation. It seems that a premature close by the web broswer on a open connection is what causes the problem. It looks like the linger function keeps trying to send the data, and never gives up. The Apache web server is running on a AIX 4.1 server with 8 PowerPC 604 processors and 512MB of ram. Its currently running 623 virtual web servers without a problem. Each virtual web server can still transfer data at about 600KB/sec. The server should be able to reach about 1950 virtual web servers before hitting the server hardlimit. I have gotten it up to 768 virtual web servers. >How-To-Repeat: Compile on an Aix 4.1 system with gcc 2.7.7 and make sure that the USE_LINGER compile option is set. Then keep trying to reload a page with lots of graphics while interrupting it to try and break the open connections. >Fix: Set the -DNO_LINGER compile option under AIX. The -DSO_LINGER option doesn't work under AIX either since it blocks the process >Audit-Trail: State-Changed-From-To: open-analyzed State-Changed-By: dgaudet State-Changed-When: Fri Aug 1 03:07:30 PDT 1997 State-Changed-Why: There is no USE_LINGER ... do you mean you added -DUSE_SO_LINGER and it stopped working? Dean From: Dean Gaudet To: apbugs@apache.org Subject: Re: os-aix/878: Server stops responding when a socket gets stuck in the CLOSE_WAIT state (fwd) Date: Sat, 16 Aug 1997 18:28:51 -0700 (PDT) ---------- Forwarded message ---------- Date: Tue, 05 Aug 1997 15:36:16 -0600 From: Clinton Work To: dgaudet@hyperreal.org Subject: Re: os-aix/878: Server stops responding when a socket gets stuck in the CLOSE_WAIT state dgaudet@hyperreal.org wrote: > > Synopsis: Server stops responding when a socket gets stuck in the CLOSE_WAIT state > > State-Changed-From-To: open-analyzed > State-Changed-By: dgaudet > State-Changed-When: Fri Aug 1 03:07:30 PDT 1997 > State-Changed-Why: > There is no USE_LINGER ... do you mean you added -DUSE_SO_LINGER and > it stopped working? > > Dean My mistake. I did mean -DUSE_SO_LINGER. I have found that apache 1.2.1 still gets locked up even without the -DUSE_SO_LINGER code under aix 4.1.5. I think it might be a problem with the AIX networking code. -- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Clinton Work CADVision Development Corp. Technical Services Suite 1810 300 5th Ave S.W. work@cadvision.com Calgary, AB, Canada T2P 3C4 CADVision Homepage: http://www.cadvision.com/ State-Changed-From-To: analyzed-feedback State-Changed-By: coar State-Changed-When: Thu May 28 04:02:50 PDT 1998 State-Changed-Why: [This is a standard response.] This Apache problem report has not been updated recently. Please reply to this message if you have any additional information about this issue, or if you have answers to any questions that have been posed to you. If there are no outstanding questions, please consider this a request to try to reproduce the problem with the latest software release, if one has been made since last contact. If we don't hear from you, this report will be closed. State-Changed-From-To: feedback-closed State-Changed-By: marc State-Changed-When: Sun Jul 19 00:52:14 PDT 1998 State-Changed-Why: No feedback, assuming resolved. >Unformatted: