nginx+php-fpm问题

环境centos5.5  lnmp   经常出现502错误或者网站突然卡  我查看php-fpm日志  
Oct 14 21:09:51.626520 [NOTICE] fpm_children_make(), line 352: child 27401 (pool default) started
Oct 14 21:09:51.628465 [NOTICE] fpm_children_make(), line 352: child 27402 (pool default) started
Oct 14 21:09:51.630462 [NOTICE] fpm_children_make(), line 352: child 27403 (pool default) started
Oct 14 21:09:51.632472 [NOTICE] fpm_children_make(), line 352: child 27404 (pool default) started
Oct 14 21:09:51.635468 [NOTICE] fpm_children_make(), line 352: child 27405 (pool default) started
65.675417 seconds from start
Oct 14 21:10:53.911169 [WARNING] fpm_children_bury(), line 215: child 25733 (pool default) exited on signal 15 SIGTERM after 65.674520 seconds from start
Oct 14 21:10:53.911246 [WARNING] fpm_children_bury(), line 215: child 25734 (pool default) exited on signal 15 SIGTERM after 65.672551 seconds from start
'/var/www/www/wwwroot/www.0505u.com/website/member/index_ad.php' (pool default) executing too slow (1.102845 sec), logging
Oct 14 21:13:46.914550 [NOTICE] fpm_got_signal(), line 48: received SIGCHLD
Oct 14 21:13:46.916310 [NOTICE] fpm_children_bury(), line 194: child 29777 stopped for tracing
Oct 14 21:13:46.916335 [NOTICE] fpm_php_trace(), line 139: about to trace 29777
Oct 14 21:13:46.916618 [NOTICE] fpm_php_trace(), line 167: finished trace of 29777
Oct 14 21:13:47.178401 [WARNING] fpm_request_check_timed_out(), line 146: child 29793, script
我在网上搜了一下 优化php-fpm参数   我优化了 但是没有效果  
求高手帮帮忙！！！！！
ps：我php版本是5.2   我在网上看到可能是php版本问题 是吗？

没有回答？？？？？？？？