ok the leaking fixed , i will past here for database for other users:

that was in my php-fpm.conf

pm = ondemand
pm.max_children = 10
pm.process_idle_timeout = 60
pm.max_requests = 1000

=============================
after i change it to this conf the leaking stoped.

pm = dynamic
pm.max_children = 10
pm.start_servers = 5
pm.min_spare_servers = 5
pm.max_spare_servers = 10
pm.max_requests = 500

i only not understand why pm = ondemand doing the leaking, does algorithem in nginx not stable or it php issue ?