When including a remote URL...

[...]
<? include('http://www.php.net') ?>
[...]

The socket to the remote server is left in CLOSE_WAIT. Eventually the Apache process runs out of file descriptors.

root@sweb-5134.atl7.sol.web.uu.net (29)# netstat -an | grep 64.246.30.37
63.111.105.8.44978   64.246.30.37.80       5840      0 24820      0 CLOSE_WAIT
63.111.105.8.44980   64.246.30.37.80       5840      0 24820      0 CLOSE_WAIT
[...]
root@sweb-5134.atl7.sol.web.uu.net (30)# pfiles 4706
4706:   /usr/local/apache/1.3.27/bin/httpd -f /etc/servers/apache/1.3.27/unixd
  Current rlimit: 262 file descriptors
[...]
  13: S_IFSOCK mode:0666 dev:229,0 ino:23031 uid:0 gid:0 size:0
      O_RDWR
        sockname: AF_INET 63.111.105.8  port: 44988
        peername: AF_INET 64.246.30.37  port: 80
  14: S_IFSOCK mode:0666 dev:229,0 ino:25628 uid:0 gid:0 size:0
      O_RDWR
        sockname: AF_INET 63.111.105.8  port: 45008
        peername: AF_INET 64.246.30.37  port: 80
[...]

This problem doesn't occur with 4.2.3 on Solaris 8.  When all of the file desriptors have been used up, the child process can't include files or lauch external processes e.g. sendmail.

[Thu Feb 20 12:02:48 2003] [error] [client 63.230.229.161] (24)Too many open files: file permissions deny server access: /export/home/xxxxxx/html/includes/common.inc   

Here's our configure line...
[..]
   env CC=gcc CFLAGS='-I/usr/local/openssl/0.9.7/include' \
   ./configure \
      --prefix=/usr/local/php/4.3.1 \
      --enable-safe-mode=yes \
      --enable-memory-limit=yes \
      --with-mysql=/usr/local/mysql/3.23.55 \
      --with-gd \
      --with-apxs=/usr/local/apache/1.3.27/bin/apxs \
      --with-jpeg-dir=/usr/local \
      --with-xpm-dir=/usr/local \
      --with-png-dir=/usr/local \
      --with-zlib-dir=/usr/local \
      --with-openssl=/usr/local/openssl/0.9.7 \
      --enable-wddx \
      --enable-debug=no
[..]