DO NOT REPLY [Bug 16872] New: - Hang upon heavy load

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http://nagoya.apache.org/bugzilla/show_bug.cgi?id=16872

Hang upon heavy load

           Summary: Hang upon heavy load
           Product: Apache httpd-2.0
           Version: 2.0.44
          Platform: PC
        OS/Version: Windows NT/2K
            Status: NEW
          Severity: Normal
          Priority: Other
         Component: Core
        AssignedTo: bugs@httpd.apache.org
        ReportedBy: andrew.liles@wheel.co.uk


Win 2K, no-ssl standard build (apache_2.0.44-win32-x86-no_ssl.msi).
Hit a static HTML page using 'ab' and the machine after, say, 2000 hits gets 
100% CPU saturation on the Apache process, cannot serve any more pages and 
does not recover.  It complains "Server ran out of threads to serve requests".


The log file (given I started Apache in Console mode) says:

[Thu Feb 06 14:01:03 2003] [notice] Parent: Created child process 724
[Thu Feb 06 14:01:03 2003] [notice] Child 724: Child process is running
[Thu Feb 06 14:01:03 2003] [notice] Child 724: Acquired the start mutex.
[Thu Feb 06 14:01:03 2003] [notice] Child 724: Starting 250 worker threads.
[Thu Feb 06 14:05:02 2003] [warn] Server ran out of threads to serve requests. 
Consider raising the ThreadsPerChild setting

*****and now I press CTRL-C to halt Apache******
[Thu Feb 06 14:05:39 2003] [notice] Parent: Received shutdown signal -- 
Shutting down the server.
[Thu Feb 06 14:05:39 2003] [notice] Child 724: Exit event signaled. Child 
process is ending.
[Thu Feb 06 14:05:40 2003] [notice] Child 724: Released the start mutex
[Thu Feb 06 14:05:41 2003] [notice] Child 724: Waiting for 250 worker threads 
to exit.
[Thu Feb 06 14:06:09 2003] [notice] Parent: Forcing termination of child 
process 184 

My ThreadsPerChild is the default for the Win build... ie 250.

This seemed very similar to bug 13991; however this case was reported on 
2.0.42 and "fixed" in 2.0.43 or rather the problem didn't reoccur.  I 
downgraded to 2.0.43 and the problem persisted.

Trying on a second Win2K box does not show the problem, therefore I have to 
assume some other environmental conditions are at play.

The failing box is Win2K (I will supply Service Pack info later) at a major 
ISP behind a firewall (unknown type).
The loadtest was run on a Linux box with highbandwidth to the Windows box.  
The load command was:
./ab -n 10000 -c 400 http://111.222.333.444/

The ok Win2K box is on the same local network as the Linux box as is Service 
Pack 3.

Would this be some IP stack issue?

Incidentally, I ran spawn-of-Satan IIS on the failing box; it performed fine 
under the load test.

What other information would be useful?

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