Comment 2 for bug 479451

Running Ubuntu 8.04
PHP 5.3.1
PHP-FPM

Had the same problem - running php-fpm on TCP 127.0.0.1:9900

It usually begins with some warning
(snippet)
Jan 07 10:47:11.704787 [WARNING] fpm_stdio_child_said(), line 167: child 14061 (pool default) said into stderr: "01 0:00:01 --:--:-- 500"
Jan 07 10:47:11.704805 [WARNING] fpm_stdio_child_said(), line 167: child 14061 (pool default) said into stderr: ""

These warnings begin to fill up the logs then eventually become
(snippet)
Jan 07 10:54:14.515903 [NOTICE] fpm_pctl_kill_all(), line 172: sending signal 9 SIGKILL to child 13779 (pool default)
Jan 07 10:54:14.515922 [NOTICE] fpm_pctl_kill_all(), line 172: sending signal 9 SIGKILL to child 13728 (pool default)
Jan 07 10:54:14.515941 [NOTICE] fpm_pctl_kill_all(), line 181: 5 children are still alive
Jan 07 10:54:14.516903 [NOTICE] fpm_got_signal(), line 48: received SIGCHLD
Jan 07 10:54:14.516946 [WARNING] fpm_children_bury(), line 217: child 14061 (pool default) exited on signal 9 SIGKILL after 1267.634537 seconds from start
Jan 07 10:54:14.518230 [NOTICE] fpm_got_signal(), line 48: received SIGCHLD
Jan 07 10:54:14.518264 [WARNING] fpm_children_bury(), line 217: child 13779 (pool default) exited on signal 9 SIGKILL after 5975.821306 seconds from start

Things work for a while on restart....