I have a problem using a callback function with ob_start, causing apache httpd instances to hang, and remain for a very long time. Each instance was using 2-4 % cpu and was causing apache to launch new processes to keep up server demand, then those servers were hanging, etc, and I was seeing an average load up in the 50-70 range (vs around 1.0 normally)

Basically:

<?

function obCallback($buffer) {
   return str_replace("hello", "hi", $buffer);
}

ob_start("obCallback");

echo "hello there";

ob_end_flush();

?>

was causing problems. I've gotten around it by using ob_get_contents then ob_end_clean and just using my function on the contents.

my configure line for php is:

'./configure' '--prefix=/usr/local' '--with-apache=/root/apachetoolbox/apache_1.3.20' '--enable-exif' '--enable-track-vars' '--with-calendar=shared' '--enable-safe-mode' '--enable-magic-quotes' '--enable-trans-sid' '--enable-wddx' '--enable-ftp' '--with-gd' '--with-zlib' '--enable-gd-native-tt' '--with-t1lib=/usr/local/lib/php/t1libs' '--with-jpeg-dir' '--with-png-dir' '--with-zlib-dir' '--with-ttf' '--with-freetype-dir' '--with-imap' '--with-mhash' '--with-mcrypt' '--with-unixODBC=/usr/local/unixODBC' '--with-pdflib=/root/apachetoolbox/src/pdflib-3.03' '--enable-shared-pdflib' '--with-snmp=/usr/local/snmp' '--with-openssl' '--with-curl=/usr/local' '--with-bcmath' '--with-mysql=/usr/local' '--with-mnogosearch=/usr/local/mnogosearch'