PHPで作ったサイトがたまに遅くなる, ガベージコレクション, session.gc_divisor, session.gc_probability ref: http://qiita.com/yuki777/items/ec9975882fd730b9133b

file0.txt

php -i|grep session.gc
session.gc_divisor => 1000 => 1000
session.gc_maxlifetime => 1440 => 1440
session.gc_probability => 1 => 1

file1.txt

session.gc_probability = 0

file2.txt

0 * * * * find /tmp -type f -name "sess_*" -mmin +120 -print0 | xargs -0 rm # 120(分)は必要に応じて変更

file3.txt

php -i|grep session.gc
session.gc_divisor => 100 => 100
session.gc_maxlifetime => 1440 => 1440
session.gc_probability => 1 => 1