From: dbarrett at vistaprint dot com
Operating system: Windows 2003 Server, 64-bit
PHP version: 5.2.6
PHP Bug Type: Reproducible crash
Bug description: exec() produces zombie processes on Windows, hangs Apache
Description:
------------
This is an intermittent but fatal problem. I cannot reproduce it on
demand, but it occurs regularly on our MediaWiki 1.12.0 site running on
Apache 2.2.8.
When invoking a non-interactive Microsoft Windows command via exec() or
shell_exec(), sometimes the resulting process will hang. Once this occurs,
most or all subsequent exec() calls (within the same Apache instance) will
hang as well. Eventually the wiki becomes unusable. The only way to kill
these processes is to restart Apache. Other traditional "kill" techniques
fail.
This is not the same as Bug #30794, which was about interactive commands
like Notepad. I'm speaking of diverse shell commands like perl.exe,
gnuplot.exe, latex.exe, and others. All of them process text input, if
that matters.
If the process is "foo" and you run exec("foo"), you wind up with several
hung processes:
foo.exe
cmd.exe*32
This may be a race condition. I ran the "handle" utility (from
sysinternals) on the hung processes. It seemed to indicate that the
processes were waiting on c:\Apache2\logs\error.log. Then handle itself
(handle64.exe) hung!
Because this is an intermittent problem, I am looking for advice on how to
debug it and report more detailed information to you. Please don't append
the generic "install the latest snapshot and let us know if the problem is
still there" message to this ticket, because I can't install an
experimental PHP release on a production server, and the problem happens
ONLY on our production server (probably because of the load), not on any of
our development or test servers.
Expected result:
----------------
exec() and shell_exec() should never hang.
--
Edit bug report at http://bugs.php.net/?id=44994&edit=1
--
Try a CVS snapshot (PHP 5.2):
http://bugs.php.net/fix.php?id=44994&r=trysnapshot52
Try a CVS snapshot (PHP 5.3):
http://bugs.php.net/fix.php?id=44994&r=trysnapshot53
Try a CVS snapshot (PHP 6.0):
http://bugs.php.net/fix.php?id=44994&r=trysnapshot60
Fixed in CVS: http://bugs.php.net/fix.php?id=44994&r=fixedcvs
Fixed in release:
http://bugs.php.net/fix.php?id=44994&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=44994&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=44994&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=44994&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=44994&r=support
Expected behavior: http://bugs.php.net/fix.php?id=44994&r=notwrong
Not enough info:
http://bugs.php.net/fix.php?id=44994&r=notenoughinfo
Submitted twice:
http://bugs.php.net/fix.php?id=44994&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=44994&r=globals
PHP 4 support discontinued: http://bugs.php.net/fix.php?id=44994&r=php4
Daylight Savings: http://bugs.php.net/fix.php?id=44994&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=44994&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=44994&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=44994&r=float
No Zend Extensions: http://bugs.php.net/fix.php?id=44994&r=nozend
MySQL Configuration Error: http://bugs.php.net/fix.php?id=44994&r=mysqlcfg
